Citations

Dent disease 1, an X‐linked inherited kidney disease caused by mutations in the CLCN5 gene, is characterized by low molecular weight proteinuria (LMWP), hypercalciuria, nephrocalcinosis, nephrolithiasis, rickets, and progressive renal failure. CLCN5 encodes the CLC‐5 protein found at the apical membrane in the kidney proximal tubule as well as endosome membranes of other tubule segments. Approximately 80 human mutations of the CLCN5 gene have been identified consisting of nonsense, missense, splice site, insertion and deletion mutations. However, the genotype and phenotype correlation are poor, and the mechanisms of CLC‐5 dysfunction that cause disease are still unclear. Moreover, there has been a lack of systematic study of CLC‐5 mutational effects on Cl − /H + exchanger activity. To address this need we used ion selective microelectrodes to monitor intracellular pH (pH i ) and intracellular Cl − concentration ([Cl i ]) of Xenopus oocytes expressing WT and mutant CLC‐5 while clamping at +40 mV. Common and novel mutations were identified in Dent patients by collaborators in the Rare Kidney Stone Consortium. The apparent H + :Cl − coupling ratio through the CLC‐5 protein was calculated using the Gibbs‐free energy equation. Cellular localization and protein trafficking of WT and mutant CLC‐5 in renal epithelial cells were also examined by immunofluorescence microscopy using eGFP/HA double‐tagged CLC‐5 and organelle‐specific markers and quantified by flow cytometry. In the presence of 104 mM Cl − (ND96), the pH i and [Cl − ] i of the CLC‐5 WT increased 340 ± 59 ×10 −4 pH unit/min and 2.8 ± 0.5 mM/min, respectively. T657S increased at a similar rate as WT, while there was a significant decrease in the rate of pH i and [Cl − ] i change for S244L, R345W, and Q629X compared to WT. Decreasing extracellular chloride to 5 mM decreased WT ClC‐5 pH i and [Cl − ] i by reversing transport: −7 ± 65 ×10 −4 pH unit/min and −0.2 ± 0.2 mM/min, respectively. Using these measurements, the stoichiometry of WT CLC‐5 was calculated to be 1.80 ± 0.02 (nCl − :H + ) in ND96, similar to the stoichiometry estimated for T657S. However, the stoichiometry was significantly altered for S244L, R345W, and Q629X. WT ClC‐5 acts as Cl − /H + exchanger at +40mV with 104 mM Cl − in the extracellular solution. Lowering extracellular Cl − reverses the transport direction, and the ClC‐5 exchanger functions at a significantly slower rate. Although S244L has normal surface expression, S244L and R345W mutations have significantly decreased pH and Cl − exchange rates in response to solution manipulations, suggesting these mutations have an altered ion exchange coupling ratio (stoichiometry). Interestingly, while R345W was retained in the ER suggesting defective protein maturation, R345W surface localization was rescued by lowering the incubation temperature from 37 to 30°C. Q629X was retained in the ER, not localized in early endosomes, and also has abolished Cl − /H + exchange activity, suggesting that Q629X affects protein maturation and trafficking while T657S is a benign, non‐disease causing mutation. These data suggest studying CLC‐5 mutational effects on both transport function and cellular localization is essential to better understand divergent phenotypes in Dent disease. Support or Funding Information NIH DK101405, U54KD083908, U54DK100227, Mayo O'Brien Urology Research Center, Mayo Clinic Rare Kidney Stone Consortium

Evidence from our laboratory has established a role for the G0/G1 Switch Gene 2 (G0S2) as the primary inhibitor of adipose lipolysis through inhibition of adipose triglyceride lipase (ATGL), the rate‐limiting enzyme in triglyceride hydrolysis. We have demonstrated that differential expression of G0S2 plays a crucial role in regulating hepatic lipid content during fasting and feeding. Hepatic G0S2 expression is also significantly increased in a pathological condition in mice with obesity‐induced hepatic steatosis or non‐alcoholic fatty liver disease (NAFLD), major metabolic health issues in today's society. Based on preliminary evidence we hypothesized there is a dynamic relationship between adipose lipolysis and hepatic G0S2 expression during physiological fasting, a relationship that has not been previously described. To better understand this relationship we evaluated the effect of free fatty acids (FFA) on G0S2 expression in liver. Interestingly, hepatic G0S2 expression during fasting results from increased free fatty acid (FFA) delivery to the liver from adipose tissue. Moreover, we identified that increases in hepatic FFA lead to increased G0S2 expression in a bi‐mechanistic manner. We investigated and subsequently determined that both transcriptional activation of G0S2 and inhibition of protein degradation are occurring in response to increased hepatic FFA levels. Utilizing a luciferase based reporter system and in vivo chromatin immunoprecipitation we found transcriptional activation of G0S2 in liver occurs in response to activation of liver‐X‐receptor α (LXRα). LXRα is a known regulator of pro‐lipogenic signaling in liver and plays a major role in cholesterol homeostasis. It has also been shown that LXRα can be activated in response to FAs most likely through its dimerization partner RXRα that is a known FA responsive transcription factor. We demonstrate G0S2 is a direct downstream target gene for LXRα. Additionally, the direct repeat 4 (DR4) LXR response element (LXRE) found 2kb upstream of the transcriptional start site in the G0S2 promoter is required for G0S2/ LXRα binding. This DR4 binding site is conserved between the human and mouse isoforms of G0S2 and is required in each for LXRα binding. Furthermore, we found that G0S2 is subject to ubiquitin modification and is degraded in a proteasome dependent pathway. Mutation analysis of the six‐lysine residues found in G0S2 provided key evidence that the lysine at position 25 is the prominent site for ubiquitylation. The G0S2 K25 mutant is more stable than wild‐type G0S2, which is consistent with the accompanying decrease in ubiquitylation. Additionally, fatty acids were able to abrogate G0S2 degradation and increase protein stability. These findings indicate that two mechanisms of expression regulation in combination with adipose lipolysis are functioning concomitantly to regulate hepatic G0S2 expression under physiological conditions. Additionally, aberrant G0S2 expression may contribute to the pathological setting with metabolically linked diseases including NAFLD. Support or Funding Information This work was supported by NIDDK grants DK089178 and 2R56DK089178 from the National Institutes of Health. Pre‐doctoral funding support for B.H. was generously provided by the Mayo Graduate School and Mayo Foundation for Medical Education & Research.

Abstract Background To evaluate the long-term clinical performance, the impact of procedural configurations and post-procedure medications in atrial fibrillation patients with percutaneous left atrial appendage occlusion (LAAO). Methods The RECORD study was a prospective, all-comers registry conducted in 39 Chinese centers that consecutively enrolling patients who received LAAO between 1st April 2019 and 31st October 2020 with minimum inclusion and exclusion criteria. Events including any death, any stroke, systemic embolism and bleeding event were collected at 1 year and adjudicated by an independent clinical event committee. Cox proportional hazard models with multivariable adjustments were applied to estimate hazard ratios (HRs) for each outcome. Results Of the 3,096 participants, 3,082 successfully received an LAAO implant and 3,013 (97.8%) completed the 1-year follow-up. Participants had a high risk of stroke (mean CHA2DS2-VASc score of 4.0) and a moderate-to-high risk of bleeding (mean HAS-BLED score of 2.4). Local anesthetic was performed in 1,287 (41.6%) patients and fluoroscopy guidance in 492 (16.0%) patients. In 1295 (42.0%) cases, one-stage combination procedures of LAAO and radiofrequency ablation or cryoablation (CA) were performed. At 1 year, the composite ischemic endpoint of death, stroke, and systemic embolism occurred in 133 (4.51%) patients. Any life-threatening, disabling or major bleeding events occurred in 71 (2.36%) patients. There was no significant association between the type of anesthesia (general versus local), modality of image guidance (TEE, ICE, or fluoroscopy) with the ischemic or bleeding events. Combination procedures of LAAO plus CA was associated with a significantly lower rate of death, stroke, or systemic embolism than performing LAAO only (3.5% versus 5.2%, HRadjusted:0.69, 95%CI:0.48-0.98, P=0.041). The commonest antithrombotic strategy was OAC | APT | APT (38.1%; corresponded to medication prescribed at discharge | 45 days | 6 months), followed by OAC | OAC | APT (27.0%). Compared with OAC | APT | APT, the OAC | OAC | APT group was associated with a higher risk of life-threatening, disabling or major bleeding (1.2% versus 2.5%, HRadjusted:0.50, 95%CI: 0.25-0.99, P=0.47); whereas the risk of death, stroke and SE was numerically similar (2.9% versus 3.0%, HRadjusted:1.05, 95%CI: 0.61-1.78, P=0.867). There was no significant difference between OAC | APT | APT and OAC+APT | APT | APT groups regarding ischemic events; however, in patients with HAS-BLED ≥ 3, OAC | APT | APT was associated with lower rates of life-threatening, disabling or major bleeding events (1.1% versus 4.8%, HRadjusted:4.55, 95%CI: 1.31-15.81, P=0.017). Conclusion In Chinese centers, patients with a WATCHMAN LAAO device had low rates of ischemic and bleeding events at 1 year. One-stage combination procedures of LAAO and catheter ablation was associated with a significantly lower rate of ischemic events than performing LAAO only.Procedural configurations to outcomesPost-LAAO antithrombotic medications

We previously showed that ablation of tumor hypoxia can sensitize tumors to immune checkpoint blockade (ICB). Here, we used a Kras +/G12D TP53 +/R172H Pdx1-Cre –derived (KPC-derived) model of pancreatic adenocarcinoma to examine the tumor response and adaptive resistance mechanisms involved in response to 2 established methods of hypoxia-reducing therapy: the hypoxia-activated prodrug TH-302 and vascular endothelial growth factor receptor 2 (VEGFR-2) blockade. The combination of both modalities normalized tumor vasculature, increased DNA damage and cell death, and delayed tumor growth. In contrast with prior cancer models, the combination did not alleviate overall tissue hypoxia or sensitize these KPC tumors to ICB therapy despite qualitative improvements to the CD8 + T cell response. Bulk tumor RNA sequencing, flow cytometry, and adoptive myeloid cell transfer suggested that treated tumor cells increased their capacity to recruit granulocytic myeloid-derived suppressor cells (G-MDSCs) through CCL9 secretion. Blockade of the CCL9/CCR1 axis could limit G-MDSC migration, and depletion of Ly6G-positive cells could sensitize tumors to the combination of TH-302, anti–VEGFR-2, and ICB. Together, these data suggest that pancreatic tumors modulate G-MDSC migration as an adaptive response to vascular normalization and that these immunosuppressive myeloid cells act in a setting of persistent hypoxia to maintain adaptive immune resistance.

Abstract Background Red blood cell (RBC) transfusion is a critical supportive therapy in cardiovascular surgery (CVS). Donor selection and testing have reduced the risk of transfusion-transmitted infections; however, risks remain from bacteria, emerging viruses, pathogens for which testing is not performed and from residual donor leukocytes. Amustaline (S-303)/glutathione (GSH) treatment pathogen reduction technology is designed to inactivate a broad spectrum of infectious agents and leucocytes in RBC concentrates. The ReCePI study is a Phase 3 clinical trial designed to evaluate the efficacy and safety of pathogen reduced RBCs transfused for acute anemia in CVS compared to conventional RBCs, and to assess the clinical significance of treatment-emergent RBC antibodies. Methods ReCePI is a prospective, multicenter, randomized, double-blinded, active-controlled, paralleldesign, non-inferiority study. Eligible subjects will be randomized up to 7 days before surgery to receive either leukoreduced Test (pathogen reduced) or Control (conventional) RBCs from surgery up to Day 7 post-surgery. The primary efficacy endpoint is the proportion of patients transfused with at least one study transfusion with an acute kidney injury (AKI) diagnosis defined as any increased serum creatinine (sCr) level ≥0.3 mg/dL (or 26.5 µmol/L) from presurgery baseline within 48±4 hours of the end of surgery. The primary safety endpoints are the proportion of patients with any treatment-emergent adverse events (TEAEs) related to study RBC transfusion through 28 days, and the proportion of patients with treatment-emergent antibodies with confirmed specificity to pathogen reduced RBCs through 75 days after the last study transfusion. With ≥292 evaluable, transfused patients (>146 per arm), the study has 80% power to demonstrate non-inferiority, defined as a Test group AKI incidence increase of no more than 50% of the Control group rate, assuming a Control incidence of 30%. Discussion RBCs are transfused to prevent tissue hypoxia caused by surgery-induced bleeding and anemia. AKI is a sensitive indicator of renal hypoxia and a novel endpoint for assessing RBC efficacy. The ReCePI study is intended to demonstrate the non-inferiority of pathogen reduced RBCs to conventional RBCs in the support of renal tissue oxygenation due to acute anemia and to characterize the incidence of treatment-related antibodies to RBC.

Abstract Polycaprolactone fumarate (PCLF) is a cross‐linkable PCL derivative extensively considered for tissue engineering applications. Although injection molding has been widely used to develop PCLF scaffolds, platforms developed using such technique lack precise control on architecture, design, and porosity required to ensure adequate cellular and tissue responses. In particular, the scaffolds should provide a suitable surface for cell attachment and proliferation, and facilitate cell–cell communication and nutrient flow. 3D printing technologies have led to new architype for biomaterial development with micro‐architecture mimicking native tissue. Here, we developed a method for 3D printing of PCLF structures using the extrusion printing technique. The crosslinking property of PCLF enabled the unique post‐processing of 3D printed scaffolds resulting in highly porous and flexible PCLF scaffolds with compressive properties imitating natural features of cancellous bone. Generated scaffolds supported excellent attachment and proliferation of mesenchymal stem cells (MSC). The high porosity of PCLF scaffolds facilitated vascularized membrane formation demonstrable with the stringency of the ex ovo chicken chorioallantoic membrane (CAM) implantation. Furthermore, upon implantation to rat calvarium defects, PCLF scaffolds enabled an exceptional new bone formation with a bone mineral density of newly formed bone mirroring native bone tissue. These studies suggest that the 3D‐printed highly porous PCLF scaffolds may serve as a suitable biomaterial platform to significantly expand the utility of the PCLF biomaterial for bone tissue engineering applications.

Abstract Purpose . To enhance an in-house graphic-processing-unit accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS). Methods and materials . A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3 cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4 cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45 mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 c.c. with range of 0.4–43.3 c.c.). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC. Results . In the water phantoms, 3D gamma passing rate (2%/2 mm/10%) between VPMC and MCsquare was 99.71 ± 0.23%. In the patient geometries, 3D gamma passing rates (3%/2 mm/10%) between VPMC/MCsquare and RayStation MC were 97.79 ± 2.21%/97.78 ± 1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45 ± 114.08 s (MCsquare) to 8.20 ± 6.42 s (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose–volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 s and the subsequent on-the-fly ‘trial-and-error’ optimization procedure took only 71.4 s on average for the selected three patients. Conclusion . VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.

Abstract Background and Aims This post hoc analysis assessed the efficacy and safety of upadacitinib in patients with moderately to severely active ulcerative colitis stratified by corticosteroid use from the ulcerative colitis Phase 3 clinical trial programme. Methods Patients were randomised [1:2] to 8 weeks’ placebo or upadacitinib 45 mg once daily; Week 8 responders were re-randomised [1:1:1] to 52 weeks’ placebo or upadacitinib 15 or 30 mg daily. Corticosteroid dose was kept stable during induction but tapered according to a protocol-defined schedule [or investigator discretion] during maintenance Weeks 0–8. Efficacy outcomes and exposure-adjusted, treatment-emergent adverse event [TEAE] rates were assessed for induction and maintenance stratified by corticosteroid use at induction baseline. Results Overall, 377/988 [38%] patients were receiving corticosteroids at induction baseline [placebo, n = 133; upadacitinib 45 mg, n = 244] and 252 [37%] of the 681 clinical responders who entered maintenance were on corticosteroids at induction baseline [n = 84 for each treatment]. Similar proportions of patients receiving upadacitinib achieved clinical remission per Adapted Mayo Score with and without baseline corticosteroids at Weeks 8 and 52. The total proportion of patients re-initiating corticosteroids was higher with placebo [24/84;29%] vs upadacitinib 15 mg [16/81; 20%)] and 30 mg [11/81; 14%]. During induction, patients receiving corticosteroids at baseline had higher rates of TEAEs, serious TEAEs, and serious infections vs those not receiving corticosteroids; however, TEAE rates were similar during maintenance after corticosteroid withdrawal. Conclusions Upadacitinib is an effective steroid-sparing treatment in patients with moderately to severely active ulcerative colitis. Clinicaltrials.gov identifiers: NCT02819635; NCT03653026

Background: Left bundle branch area pacing (LBBAP) has rapidly emerged as a promising modality of physiologic pacing and has demonstrated excellent lead stability. In this retrospective study, we evaluate whether this pacing modality can allow concomitant atrioventricular node (AVN) ablation and same-day dismissal. Methods: Twenty-four consecutive patients (female 63%, male 37%) with an average age of 78 ± 5 years were admitted for pacemaker (75%)/defibrillator (25%) implantations and concomitant AVN ablation. Device implantation with LBBAP was performed first, followed by concomitant AVN ablation through left axillary vein access to allow for quicker post-procedure ambulation. The patients were discharged on the same day after satisfactory post-ambulation device checks. Results: LBBAP was successful in 22 patients (92% in total, 20 patients had an LBBP and two patients had a likely LBBP), followed by AVN ablation from left axillary vein access (21/24, 88%). All patients had successful post-op chest x-rays, post-ambulation device checks, and were discharged on the same day. After a mean follow up of three months, no major complications occurred, such as LBBA lead dislodgement requiring a lead revision. The LBBA lead pacing parameters immediately after implantation vs. three-month follow up were a capture threshold of 0.8 ± 0.3 V@0.4 ms vs. 0.6 ± 0.3 V@0.4 ms, sensing 9.9 ± 3.9 mV vs. 10.4 ± 4.1 mV, and impedance of 710 ± 216 ohm vs. 544 ± 110 ohm. The QRS duration before and after AVN ablation was 117 ± 32 ms vs. 123 ± 14 ms. Mean LVEF before and three months after the implantation was 44 ± 14% vs. 46 ± 12%. Conclusion: LBBA pacing not only offers physiologic pacing, but also allows for a concomitant AVN ablation approach from the left axillary vein and safe same-day hospital dismissal.

AbstractBackgroundAppropriate time for ejection fraction (EF) reassessment after revascularization in patients with left ventricular dysfunction has not been investigated comprehensively, although 3 months after revascularization is recommended to stratify the risk of sudden cardiac death (SCD).HypothesisEF reassessed within different timeframe after revascularization may have incosistent contribution for risk stratification of SCD.MethodsPatients who had EF ≤ 40% before revascularization and had EF reassessment at least once during follow‐up were included. The role of early (<3 months) versus late (3–12 months) EF measurements in prediction of all‐cause mortality and SCD were compared.ResultsA total of 1589 patients were identified. EF reassessed <3 months was lower than EF reassessed within 3–12 months (42.1 ± 9.7% vs. 45.8 ± 10.8%; p < .01). Among 1069 patients who had EF reassessed <3 months, EF ≤ 35% was associated with a higher risk of all‐cause mortality (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.22–2.29; p < .01), but had no association with the risk of SCD (HR, 1.44; 95% CI, 0.84–2.48; p = .18). By contrast, among 595 patients who had EF reassessed within 3–12 months, EF ≤ 35% was associated with higher risks of both all‐cause death (HR, 1.81; 95% CI, 1.06–3.10; p = .03) and SCD (HR, 2.71; 95% CI, 1.31–5.61; p < .01). The relative contribution of SCD to all‐cause death was higher in patients with EF ≤ 35% than patients with EF > 35% when EF was reassessed within 3–12 months (p = .04). However, when EF was reassessed <3 months, the mode of death was similar in patients with EF ≤ 35% versus >35% (p = .85).Conclusions3 to 12 months after revascularization may be appropriate for cardiac function reassessment and SCD risk stratification.