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Background The management of osteochondral lesions of the talus (OLT) is challenging, with 2 main options being conservative and surgical management. Orthobiologic therapies come to bridge the gap between these 2 options; however, inconsistencies in indication, composition, and heterogeneous evidence limit clinical decision-making. To address these challenges, 3 International Congress Meetings on Cartilage Repair of the Ankle were convened in Pittsburgh, USA (2017), Dublin, Ireland (2019), and New York, USA (2025) to establish agreement on the role of conservative management and injectable orthobiologic strategies in the treatment of OLT. Methods Seventy-five multidisciplinary experts from over 25 countries and 1 territory participated in a structured Delphi-based consensus process. Blinded surveys, structured questionnaires, and in-person discussions were used to develop and refine statements, supported by literature review and graded evidence (A1–E). Consensus strength was defined as consensus (51%-74%), strong consensus (75%-99%), or unanimous (100%) Results In total, 29 consensus statements were achieved across the 3 meetings. Strong agreement was reached regarding indications and expected outcomes of conservative management, including the role of immobilization and appropriate timing for surgical intervention. Orthobiologic injections, including platelet-rich plasma, concentrated bone marrow aspirate, and hyaluronic acid, were considered appropriate in select patients with persistent symptoms, although no superiority was demonstrated among formulations, preparation methods, or injection strategies. When used as adjuncts to surgical procedures, orthobiologics may improve radiological outcomes, with limited evidence for improvement in clinical outcomes. Technical considerations, including preferred harvest sites and a lack of standardized preparation protocols, were identified, along with key principles for patient counseling Conclusion These international consensus statements establish a standardized framework for the conservative management and use of injectable orthobiologic therapies in OLT. By clarifying indications, technical considerations, and current limitations, this work aims to improve consistency in clinical practice, guide treatment decision-making, and inform future research.

Poststenotic dilatation in renal artery stenosis, evaluated at abdominal CT, might be related to stenotic kidney damage and inflammation, particularly to monocyte chemoattractant protein-1 release.

Abstract Importance Mesenchymal stromal cells (MSCs) possess therapeutic properties that mediate repair. Obesity impairs MSC functionality and therapeutic efficacy, possibly by eliciting dynamic modifications of epigenetic markers, like 5-hydroxymethylcytosine (5hmC). Objective We hypothesized that human obesity alters the 5hmC landscape and anti-inflammatory capacity of adipose tissue-derived MSCs to activate the prominent inflammatory signaling mediator Interleukin (IL)-1β. Design, Setting, Participants, Intervention Adipose tissue samples were collected from obese and lean individuals (body mass index ≥30 or <30 kg/m2, respectively, n = 11 each) during weight-loss or kidney donation surgery. Main Outcomes and Measures MSCs were harvested and analyzed for 5hmC profiles (MeDIP-seq) and mRNA expression (RNA-seq) (n = 5 each). Subsequently, MSCs or a vehicle were injected into mice, (n = 6 each) and two-weeks later, kidneys were evaluated using in-vivo magnetic resonance imaging and ex vivo studies. The role of IL-1β was then studied in-vitro in MSC-induced immunomodulation using siRNA in macrophages. Results Compared to MSC from lean patients, obese-MSC genes showed 2087 differential 5hmC modifications and 175 differential mRNA expression. Among them, 14 genes with overlapping alterations were involved in regulation of cytokine production, prominently IL-1β. Injecting obese MSCs elevated renal expression of IL-1β and M1 macrophage count but lowered kidney perfusion. Silencing IL-1β in obese-MSCs in vitro reduced M1 phenotype switching in co-incubated macrophages. Conclusions and Relevance Obesity induces epigenetic and gene expression changes in MSCs, particularly in IL-1β, associated with impaired anti-inflammatory functionality of MSCs. Targeting IL-1β could be a useful therapeutic approach to modulate the decline in MSC functionality resulting from obesity.

The intrinsic reparative capacity of the adult mammalian kidney is restricted to the ability of scattered tubular-like cells (STCs) to repair damaged kidney cells. Our study provides evidence that chronic renal ischemia alters the mRNA/miRNA profile of angiogenic/vascular development genes of swine STCs, limiting their potential to repair injured tubular cells. Our observations may assist in developing new therapies to improve renal repair in individuals with chronic renal ischemia.

Metabolic syndrome (MetS) is associated with low-grade inflammation, which can be exacerbated by renal artery stenosis (RAS) and renovascular hypertension, potentially worsening outcomes through pro-inflammatory cytokines. This study investigated whether mesenchymal stem/stromal cells (MSCs) could reduce fat inflammation in pigs with MetS and RAS. Twenty-four pigs were divided into Lean (control), MetS, MetS + RAS, and MetS + RAS + MSCs. In the MSC-treated group, autologous adipose-derived MSCs (107 cells) were injected into the renal artery six weeks after RAS induction. After four weeks, fat volumes and inflammatory markers were assessed. MSC treatment reduced levels of pro-inflammatory cytokines (MCP-1, TNF-a, IL-6) in the renal vein blood and in perirenal fat. The MSCs also decreased fat fibrosis, restored adipocyte size, and altered adipogenesis-related gene expression, particularly in the perirenal fat. These effects were less pronounced in subcutaneous fat. The MSC therapy attenuated fat inflammation and improved metabolic outcomes in pigs with MetS + RAS, suggesting that adipose-derived MSCs may offer a promising therapeutic approach for metabolic disorders.

AbstractThe Clinical and Laboratory Standards Institute (CLSI) H62—Validation of Assays Performed by Flow Cytometry guideline, released in 2021, provides recommendations for platform workflow and quality system essentials, instrument setup and standardization, assay development and optimization and fit‐for‐purpose analytical method validation. In addition, CLSI H62 includes some recommendations for the validation strategies after a validated flow cytometric method has been modified. This manuscript builds on those recommendations and discusses the impact of different types of assay modifications on assay performance. Recommendations regarding which validation parameters to evaluate depending on the type of modification are provided. The impact of assay modification on the assay's intended use is discussed. When recommending minor deviations from the CLSI H62 process for a laboratory‐initiated assay revision (e.g., specimen numbers for sensitivity, specificity, or precision studies), a rationale based on expert opinion is provided with the understanding that not every laboratory, assay type, and circumstance can be comprehensively addressed in this paper. These recommendations are meant as a practical recommendation and are not intended to be restrictive, prescriptive, or understood as necessarily sufficient to meet every specific requirement from regulatory bodies (e.g., FDA or New York State Department of Health).

The single-cell platform mass cytometry (CyTOF) enables detection of significant changes in one million of renal cells, especially in subsets of immune cells in ischemic human kidneys distal to renal artery stenosis (RAS). We found that pro-repair cell types such as scattered tubular-progenitor-like cells, aged neutrophils, and regulatory B cells show a compensatory increase in RAS. Immune cell phenotype changes may reflect ongoing inflammation and impaired immune defense capability in the kidneys.

Background Superimposition of the metabolic syndrome (MetS) on renovascular disease (RVD) amplifies intrarenal microvascular loss. Extracellular vesicles (EVs) released from adipose tissue‐derived mesenchymal stem/stromal cells (MSCs) may mediate their paracrine effect, but their efficacy to protect the renal microcirculation in RVD complicated by MetS remains unclear. Using a novel swine model, we tested the hypothesis that EVs would attenuate microvascular loss in MetS+RVD. Methods Four groups of pigs (n=7 each) were studied after 16 weeks of diet‐induced MetS and unilateral RVD (MetS+RVD), MetS+RVD treated 4 weeks earlier with a single intra‐renal delivery of pre‐labeled EVs harvested from autologous MSCs, and Lean and MetS Sham controls. Stenotic‐kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were measured in‐vivo (fast CT), whereas EV characteristics, renal microvascular architecture (micro‐CT), and injury pathways ex‐vivo. Results mRNA sequencing of EVs and their parent MSCs revealed that EVs were enriched with pro‐angiogenic genes, including vascular endothelial growth factor (VEGF)‐A, VEGF–C, and Von Willebrand Factor (vWF)‐A Domain Containing‐1 (VWA)‐1 (). In addition, protein expression of VEGF and vWF was higher in EVs compared to MSCs (). EVs were detected in the stenotic‐kidney ex‐vivo internalized by tubular and endothelial cells. EVs restored renal expression of the pro‐angiogenic factors VEGF, Notch‐1, and Notch ligand delta‐like‐4 (DLL4) and improved cortical microvascular density (). Tubulointerstitial fibrosis increased and RBF and GFR decreased in MetS+RVD vs. MetS, but were restored in MetS+RVD+EV (). Conclusions Intra‐renal delivery of MSC‐derived EVs bearing pro‐angiogenic properties in swine MetS+RVD restored stenotic‐kidney microcirculation, and in turn its hemodynamics and function. Our study suggests a novel therapeutic potential for MSC‐derived EVs in restoring renal function in chronic experimental MetS+RVD. Support or Funding Information This study was partly supported by NIH grant numbers DK73608, DK104273, HL123160, and DK102325, DK106427, the Mayo Clinic Center for Regenerative Medicine, and the Mayo Clinic Mary Kathryn and Michael B. Panitch Career Development Award.

Injection of A-MSC-derived EVs harvested from patients who are lean can resolve myocardial injury in mice with experimental renovascular hypertension more effectively than A-MSC-derived EVs from patients with obesity. These observations underscore and might have important ramifications for the self-healing capacity of patients with obesity and for the use of autologous EVs as a regenerative tool.