Citations

Significance Statement The arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis, but several studies have shown that the primary patency rate at 1 year is approximately 60%. Percutaneous transluminal angioplasty (PTA) is the first line of treatment for AVF stenosis. However, the rate of restenosis after angioplasty is high and the primary patency rate after PTA treatment in AVFs at 6, 12, and 24 months is 61%, 42%, and 35%, respectively. Currently, no durable therapies prolong patency after angioplasty. This paper describes the use of adipose-derived mesenchymal stem cells to reduce stenosis after PTA treatment in a murine AVF model and provides rationale for potential clinical use. Background Percutaneous transluminal angioplasty (PTA) is the first line of treatment for stenosis in the arteriovenous fistula (AVF) created to provide access for hemodialysis, but resenosis still occurs. Transplants of adipose-derived mesenchymal stem cells (AMSCs) labeled with green fluorescent protein (GFP) to the adventitia could reduce pro-inflammatory gene expression, possibly restoring patency in a murine model of PTA for venous stenosis. Methods Partial nephrectomy of male C57BL/6J mice induced CKD. Placement of the AVF was 28 days later and, 14 days after that, PTA of the stenotic outflow vein was performed with delivery of either vehicle control or AMSCs (5×10 5 ) to the adventitia of the vein. Mice were euthanized 3 days later and gene expression for interleukin-1 beta (IL-1 β ) and tumor necrosis factor-alpha TNF- α ) analyzed, and histopathologic analysis performed on day 14 and 28. GFP (+) AMSCs were tracked after transplantation for up to 28 days and Doppler ultrasound performed weekly after AVF creation. Results Gene and protein expression of IL-1 β and TNF- α, fibrosis, proliferation, apoptosis and smooth muscle actin decreased, and the proportions of macrophage types (M2/M1) shifted in a manner consistent with less inflammation in AMSC-transplanted vessels compared to controls. After PTA, AMSC-treated vessels had significantly higher wall shear stress, average peak, and mean velocity, with increased lumen vessel area and decreased neointima/media area ratio compared to the control group. At 28 days after delivery, GFP (+) AMSC were present in the adventitia of the outflow vein. Conclusions AMSC-treated vessels had improved vascular remodeling with decreased proinflammatory gene expression, inflammation, and fibrotic staining compared to untreated vessels.

Abstract An international consensus on antineutrophil cytoplasm antibodies (ANCA) testing in eosinophilic granulomatosis with polyangiitis (EGPA) is presented. ANCA, specific for myeloperoxidase (MPO), can be detected in 30–35% of patients with EGPA. MPO-ANCA should be tested with antigen-specific immunoassays in any patient with eosinophilic asthma and clinical features suggesting EGPA, including constitutional symptoms; purpura; polyneuropathy; unexplained heart, gastrointestinal, or kidney disease; and/or pulmonary infiltrates or hemorrhage. A positive MPO-ANCA result contributes to the diagnostic workup for EGPA. Patients with MPO-ANCA–associated EGPA have vasculitis features, such as glomerulonephritis, neuropathy, and skin manifestations, more frequently than patients with ANCA-negative EGPA. However, the presence of MPO-ANCA is neither sensitive nor specific enough to identify whether a patient should be subclassified as having “vasculitic” or “eosinophilic” EGPA. At present, ANCA status cannot guide treatment decisions, that is, whether cyclophosphamide, rituximab, or mepolizumab should be added to conventional glucocorticoid treatment. In EGPA, monitoring of ANCA is only useful when MPO-ANCA was tested positive at disease onset.

Significance Owing to potential advantages including ease of use, airtight or watertight sealing, and minimal tissue damage, bioadhesives have been intensively studied and developed as an alternative to sutures and staples to close wounds, achieve hemostasis, and attach and immobilize implantable devices. However, existing bioadhesives have limitations including slow adhesion formation, weak bonding, low biocompatibility, poor mechanical match with tissues, and/or lack of triggerable benign detachment. In this work, we report a bioadhesive capable of instant tough adhesion and triggerable benign detachment that can potentially address all the above-mentioned limitations. The current work not only develops a bioadhesive with superior performances but also advances the understanding of wet adhesion.

AbstractBackgroundEndobronchial ultrasound‐guided transbronchial lung biopsy (EBUS‐TBLB) and fluorodeoxyglucose positron emission tomography (FDG‐PET) have been widely used in the diagnosis of peripheral pulmonary lesions (PPLs). This study was conducted to determine the diagnostic value of EBUS‐TBLB combined with FDG‐PET in the assessment of PPLs.MethodsThe clinical data of 76 patients with PPLs who received both FDG‐PET and EBUS‐TBLB from January 2016 to February 2018 were retrospectively evaluated. Further subgroup analysis was performed according to lesion diameter (≤20 mm or >20 mm). Related diagnostic indices were calculated and compared between groups.ResultsWhen combining EBUS‐TBLB with FDG‐PET, the diagnostic accuracy rate, sensitivity, specificity, Youden's index, positive predictive value, and negative predictive value for PPLs were 86.8%, 90.2%, 73.3%, 63.5%, 93.2%, and 64.7%, respectively. In addition, the diagnostic accuracy rate of the combined approach was significantly higher than the single EBUS‐TBLB and FDG‐PET (P < 0.01 and P < 0.05, respectively), and its Youden's index was also at a higher level. When stratified by lesion diameter, the combined approach showed a significantly higher diagnostic accuracy rate (P < 0.05) and a higher Youden's index for PPLs >20 mm than PPLs ≤20 mm. In addition, we found that positive bronchus sign and probe within the probe were two important factors conducing to enhancing the diagnostic accuracy rate for EBUS‐TBLB.ConclusionsAn integrated approach combining EBUS‐TBLB with FDG‐PET is particularly useful for diagnosing PPLs, and the improved diagnostic yields were especially evident for PPLs >20 mm.

AimsMany biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots.MethodsA total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded.ResultsThe mean load to create a 3 mm gap formation in the DRSK and DRS groups was significantly higher than in the SB group. The DRSK group had the highest load to failure with a mean ultimate failure load of 395.0 N (SD 56.8) compared to the SB and DRS groups, which recorded 147.1 N (SD 34.3) and 285.9 N (SD 89.8), respectively (p < 0.001 for both). The DRS group showed a significantly higher mean failure load than the SB group (p = 0.006). Both the DRS and DRSK groups showed significantly higher mean stiffness than the SB group.ConclusionThe biomechanical properties of the DRS technique were significantly improved compared to the SB technique. The DRS technique with medial row knots showed superior biomechanical performance than the DRS technique alone.

Abstract Background and Aims Novel therapies are needed to address the increasing prevalence of chronic kidney disease. Mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (EVs) augment tissue repair. EVs have practical benefits, but their efficacy relative to MSCs is incompletely understood. We tested the hypothesis that EVs are as effective as MSCs in protecting the stenotic kidney but target different injury pathways. Method Pigs were studied after 16 weeks of renal injury achieved by diet-induced metabolic syndrome (Mets) and renal artery stenosis (RAS). Pigs were untreated or treated four weeks earlier with a single intrarenal delivery of autologous adipose tissue-derived MSCs (1 × 107) or EVs (1 × 1010). Lean pigs and sham RAS served as controls (n=6 each). Stenotic kidney function was studied in-vivo using CT. Histopathology and expression of necroptosis markers (RIPK-1 and RIPK-3), inflammatory and growth factors (angiopoeitin-1 and VEGF) was studied ex-vivo. Results Stenotic-kidney glomerular filtration rate and blood flow in Mets+RAS were both lower than Mets, increased in Mets+RAS+MSCs, and further improved in Mets+RAS+EV. Both MSCs and EVs improved renal function, hypoxia, and decreased renal fibrosis and apoptosis. MSC were slightly more effective in preserving microvascular density (0.02-0.2mm in diameter), and prominently attenuated renal inflammation. However, EVs more significantly upregulated growth-factor expression and decreased necropotosis. Conclusion: Adipose tissue-derived MSCs and their EVs both improve stenotic kidney function and decrease tissue injury in Mets+RAS. MSCs more effectively preserve the microcirculation, while EVs bestow better preservation of renal cellular integrity. These findings encourage further exploration of this novel approach to attenuate renal injury.

Abstract Background and Aims Endothelial progenitor cells (EPCs) patrol the circulation and contribute to endothelial cell regeneration and tissue revascularization. Atherosclerotic renal artery stenosis (ARAS) induces microvascular loss in the stenotic kidney. A regimen of low–energy shockwave therapy (SW) induces angiogenesis and reduces chronic ischemia, but the mechanism remains unclear. This study tested the hypothesis that SW increases EPCs homing to the stenotic kidney and increases renal capillary regeneration in a unilateral ARAS swine model. Method Domestic pigs were randomized to normal control or unilateral ARAS (induced by a local irritant coil in the renal artery and a high-fat diet). ARAS pigs were treated with low-energy SW (0.1 mJ/mm2) or sham (n=6 each group), bi-weekly for 3 consecutive weeks, starting after 3 weeks of ARAS. Blood samples for EPCs (CD34+ and KDR+ by flow cytometry) and the homing factor SDF-1 were collected 4 weeks after completion of SW treatment from the inferior vena cava (IVC) and the stenotic kidney (STK) vein and artery. Urine was collected from the urinary bladder. Kidneys were studied ex vivo for morphology and expression of an endothelial cell marker (CD31) and the pro- angiogenic growth factor angiopoietin (Ang)-1. Results In ARAS, tubulointerstitial fibrosis, tubular score, urinary protein, serum creatinine and mean arterial pressure were significantly increased and capillary count (Fig. 1A) decreased (P&lt;0.05 vs. control), but all markedly improved in ARAS+SW (P&lt;0.05 vs. ARAS). EPC number was decreased in the IVC and renal artery of ARAS pigs (Fig. 1B), but improved in ARAS+SW. SDF-1 levels in the IVC, STK vein and artery, and Ang-1 expression in the kidney of ARAS+SW, were all increased (P&lt;0.05 vs. ARAS). Conclusion Low-energy shockwave improves ischemic kidney capillary density, which is associated with and may be at least in part mediated by promoting EPC mobilization and homing to the stenotic kidney.

Abstract Background and Aims Tumor necrosis factor-α-induced gene/protein (TSG)-6 is a key factor influencing mesenchymal stem cells (MSCs) immunomodulatory properties, but its renoprotective efficacy is unknown. Using a novel swine model of renal artery stenosis (RAS) complicated by metabolic syndrome (Mets), we assessed the therapeutic effects of adipose tissue-derived MSCs-produced TSG-6 and mechanisms underlying the immunomodulatory properties of MSCs. Method Five groups of pigs (n=6 each) were studied after 16 weeks of diet-induced Mets and unilateral RAS (Mets+RAS), either untreated or treated 4 weeks earlier with a single intra-renal delivery of autologous posrcine adipose tissue-derived MSCs (pMSC). Lean, Mets, and RAS shams served as controls. We studied renal function in vivo (using CT imaging) and kidney histopathology and macrophage phenotype ex vivo. In vitro, TSG-6 levels were measured in conditioned media of human MSCs (hMSCs) incubated with or without TNF-α. Additionally, levels of the tubular injury marker LDH were measured in conditioned media after co-culturing macrophages with injured HK-2 cells (achieved by TNF-α and antimycin-A, AMA) with or without addition of TSG-6. The effects of TSG-6 on macrophage phenotype (M1/M2), adhesion, and migration capability were determined. Results Mets+RAS pigs showed increased renal M1 macrophages and renal vein TNF-α levels. After p-MSCs delivery, renal vein TSG-6 increased and TNF-α decreased, M1 macrophage switched to M2 (Fig. A),, renal function improved, and fibrosis alleviated. In vitro, TNF-α increased TSG-6 secretion by h-MSCs. TSG-6 decreased LDH release from injured HK-2, induced a macrophage phenotypic switch from M1 to M2 (Fig. B), and reduced M1 macrophage adhesion and migration (Fig. C). Conclusion TNF-α-induced TSG-6 release from MSCs in vivo and in vitro may decrease renal tubular cells injury, which is associated with and may be at least in part mediated by regulating macrophage function and phenotype.

STK38, a reader of histone H4 ufmylation, regulates ATM activation.