Citations

Abstract P2x purinoreceptor 7 (P2RX7), an ATP-gated ion channel, is known to play pivotal roles in the progression of Alzheimer’s disease (AD), although its cell type-specific pathological mechanisms have yet to be elucidated. Here, we show that genetic deletion of P2rx7 mitigates brain atrophy, tau accumulation and cognitive impairment in PS19 tauopathy mice. Specific deletion of P2rx7 in microglia, but not astrocytes, significantly suppresses tau propagation from the entorhinal cortex to CA1 in the hippocampus, an early event in AD pathology. Single-cell (sc)-RNA sequencing of mouse brains revealed specific P2rx7 expression in microglia, inducing inflammatory changes accompanied by elevated extracellular vesicles (EVs) secretion in PS19 mice. Brain-derived EVs (BDEVs) proteome demonstrated that P2RX7 increases EV cargo loading of tau and mitochondrial molecules in BDEVs from PS19 mice, which was further validated by single-molecule super-resolution. Notably, following the injection of BDEVs isolated from PS19 mice with or without P2rx7 deficiency, the microglial transcriptome of recipient mice revealed enriched DNA-sensing and type II interferon signaling in response to BDEVs from PS19 mice, which was diminished in the group injected with P2rx7-deficient BDEVs. Thus, our results indicate that P2RX7 regulates EV-mediated tau and mitochondrial transfer and inflammatory activation in microglia with increased EV secretion, thereby contributing to tauopathy and neurodegeneration, highlighting the therapeutic potential of targeting the P2RX7-EV axis in AD.

Purpose To establish international expert consensus on surgical techniques, complications, and rehabilitation protocols for lateral extra‐articular procedures (LEAPs) performed adjunctively with anterior cruciate ligament reconstruction. Methods Fifty‐five knee surgeons from 17 countries on 5 continents completed a 3‐round modified Delphi process. In the final round, 16 statements on LEAP techniques and complications were scored on a 5‐point Likert scale; ≥75% “agree/strongly agree” constituted consensus. When appropriate, strength of recommendation was graded. Statements lacking support were revised until consensus or abandonment. Results Six statements achieved unanimous consensus (100%), 2 had strong consensus (90%‐99.9%), and 3 reached consensus (75%‐89.9%); 4 were removed. Key technical recommendations were as follows: (1) in iliotibial band procedures, the graft strip should pass beneath the lateral collateral ligament; (2) an anatomic technique is mandatory for anterolateral ligament reconstruction; and (3) no single LEAP is clinically superior to another. Unanimous agreement indicated that modern LEAPs do not increase lateral compartment osteoarthritis risk, carry a low complication rate, and do not necessitate changes to rehabilitation or return‐to‐play timelines. Conclusions Consensus defined core surgical principles and confirmed the safety of adding LEAPs to anterior cruciate ligament reconstruction. When an iliotibial band graft is used, it should be routed deep to the lateral collateral ligament and fixed between 0° and 60° of knee flexion under low tension. For anterolateral ligament reconstruction, femoral fixation should be in full extension at a posterior‐proximal point relative to the lateral epicondyle. Although no single LEAP proved superiority, adherence to these principles permits safe, effective surgery without altering standard rehabilitation or return‐to‐sport protocols and without increasing osteoarthritis risk. Level of Evidence Level V, expert opinion.

Purpose To define expert consensus on whether and how lateral extra‐articular procedures (LEAPs) should accompany anterior cruciate ligament (ACL) reconstruction to optimize outcomes in ACL‐deficient knees. Methods Fifty‐five knee surgeons from 17 countries on 5 continents completed a 3‐round modified Delphi process. Twenty‐one statements on patient selection for combined ACL reconstruction (ACLR) + LEAPs were graded on 5‐point Likert scales; ≥75% “agree/strongly agree” signified consensus. Strength of recommendation was ranked, and statements failing the threshold were revised or discarded after discussion. Results One statement achieved unanimous agreement (100%): it is strongly recommended to add a LEAP for active patients ≤25 years receiving hamstring‐autograft ACLR to reduce graft failure. Strong consensus (≥90%) supported LEAPs in primary ACLR when grade 3 pivot shift (97.9%), knee hyperextension (97.9%), skeletally immature status (79.5%), revision ACLR (91.5%), return to pivoting sports (93.2%), active patients ≤25 years using nonhamstring grafts (90.7%), grade 3 Lachman test (90%), and when multiple relative risk factors coexist (statement 36, 97.1%). Consensus (75%‐89.9%) favored LEAPs for chronic symptomatic ACL deficiency (86.1%), posterior tibial slope >12° (85.7%), and a history of contralateral ACL injury (88.9%). Eight statements did not reach consensus regarding small‐diameter autografts, female athletes, imaging signs of anterolateral injury (e.g., Segond fracture, lateral femoral‐notch sign), and concomitant meniscal procedures. One statement on LEAPs with primary ACL repair was withdrawn because the project focused on reconstruction. Conclusions International experts strongly recommend adding a LEAP in young active patients undergoing hamstring‐autograft ACLR and in cases of high‐grade rotational or anterior laxity, knee hyperextension, revision surgery, or returning to pivoting sports. Unresolved issues include small graft size, female athletes, imaging findings of rotational instability, and concurrent meniscal procedures, highlighting priorities for future research. Level of Evidence Level V, expert opinion.

Background/Objective: Noninvasive PET imaging-based assessment of PD-L1 expression is of high clinical value for better patient selection and treatment response rates to PD-L1 immunotherapies. Due to their shorter biological half-life and faster clearance from the blood pool, radiolabeled antibody fragments are an attractive alternative for imaging than their full-length IgG counterpart. This work investigated the radiosynthesis and in vitro cell uptake of anti-PD-L1-B11-nanobody radiolabeled with 44Sc (t1/2 = 4.04 h) as an alternative to anti-PD-L1-B11-IgG, better suited for longer half-life radioisotopes such as 89Zr (t1/2 = 78.41 h). Methods: The proteins were conjugated with p-SCN-Bn-DTPA and radiolabeled at room temperature with 44Sc, achieving a radiochemical yield of a RCY of 94.8 ± 3.1% (n = 3) for [44Sc]Sc-B11-IgG and 73.6 ± 12.1% (n = 3) for [44Sc]Sc-B11-nanobody, before purification. Results: Significantly higher uptake in the PD-L1+ cells than PD-L1KO cells was observed for both probes. However, high non-specific uptake, particularly of the radiolabeled B11-nanobody, was also observed which may negatively impact its potential as a molecular imaging probe. Conclusions: Due to the high non-specific uptake in vitro, the 44Sc radiolabeled nanobody was not progressed to further in vivo evaluation. These results should, however, not discourage future evaluations of other nanobody based probes radiolabeled with 44Sc, due to their well-matched biological and physical half-life.

Aims Testicular sex cord‐stromal tumours (TSCSTs) are relatively rare, accounting for ~5% of all testicular neoplasms. They were historically classified into Leydig cell tumour, Sertoli cell tumour, granulosa cell tumour, and unclassified sex cord‐stromal tumour. More recently, classification was expanded to incorporate additional histologic types, including some associated with inherited cancer predisposition syndromes. However, the classification of TSCSTs still relies entirely on morphology, with some tumour types being defined based on their resemblance to ovarian counterparts. In recent years, molecular studies have identified drivers and genomic alterations associated with aggressive behaviour and progression; however, these findings have not yet impacted classification and management. Methods and results Under sponsorship of the International Society of Urological Pathology (ISUP) and the Genitourinary Pathology Society (GUPS), a group of genitourinary pathologists was assembled in 2023 with the aim of assessing how to use these new data to improve the classification and management of TSCSTs. Conclusions This paper summarizes the recommendations derived from the consensus activities and the first meeting of the te sticular s ex cord‐ s tromal t umour (TESST) group (held at Johns Hopkins Hospital, Baltimore, USA, 3/23/2024).

Activation of oncogenes, such as through mutations in Kirsten rat sarcoma viral oncogene homolog (KRAS), triggers profound disruptions in cellular homeostasis that set off a cascade of stress responses. These responses enable cells to cope with the array of challenges encountered during tumorigenesis by activating defense mechanisms that promote adaptation and survival. Key components of this oncogenic stress response include heat shock proteins, the ubiquitin-proteasome system, autophagy, nuclear factor erythroid 2-related factor 2–antioxidant response element signaling, DNA damage response proteins, p53, redox-regulating proteins, and stress granules. This review concentrates on KRAS-driven oncogenic transformation, as KRAS mutations are among the most common in human cancers, accounting for over 90% of pancreatic ductal adenocarcinoma cases, around 30% of lung cancers, and approximately 50% of colorectal cancers. We examine the intricate molecular interplay between oncogenic stress and the associated cellular defense mechanisms, emphasizing the key molecular events that follow KRAS activation. Importantly, the very pathways that allow cancer cells to adapt to oncogenic stress also offer novel therapeutic opportunities. By selectively targeting pivotal regulators within these stress response pathways, we can potentially disrupt the survival mechanisms of cancer cells. This strategy not only promises to enhance the effectiveness of existing treatments but also paves the way for the development of innovative therapies designed to combat tumor progression. In essence, exploiting oncogenic stress responses represents an original and promising therapeutic approach in the fight against cancer.

ABSTRACT Background The Society of Pediatric Liver Transplantation (SPLIT) has undergone tremendous growth with > 45 sites contributing data focusing on improving outcomes in pediatric liver transplantation (LT). We report and compare outcomes from the SPLIT Registry. Methods Patients < 18 years with first‐time LT only enrolled into the SPLIT Registry between 2011 and 2023 were included. Data was stratified into eras from the last published registry update (era 1: 2011–2018, era 2: 2018–2023). Results Three thousand five hundred four participants from 47 centers were included (era 1: n = 2159; era 2: n = 1345). Age distribution differed with more children < 1 year. of age at LT in era 2 (era 1: 29% vs. era 2: 33%, p = 0.01). Indications for LT were similar, with biliary atresia (38.8%) and metabolic disease (16.0%) being most common. Exception point use was higher in era 2 (era 1: 45% vs. era 2: 56%, p < 0.001). No difference in graft type (deceased: 81% era 1 vs. 78% era 2, p = 0.78), patient survival at 90 days (era 1: 98.7% vs. era 2: 98.3%), 1 year (era 1: 97.2 vs. era 2: 96.8%), or 3 years (era 1: 95.3% vs. era 2: 95.2%) was noted. Rate of hepatic artery thrombosis was lower in era 2 (era 1: 7% vs. era 2: 5%, p = 0.02). Conclusions Trends in pediatric LT within SPLIT note similar LT indications and graft type, higher utilization of exception points, and lower HAT rates despite transplanting more children < 10 kg. This data underscores the evolution of pediatric LT toward higher survivability and overall patient outcomes.