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Item 153. Quantification of Lymphangiogenesis in Murine Lymphedema Tail Model Using Intravital Microscopy(Wolters Kluwer, 2023-05-19) Mohan, Ganesh; Khan, Imran; Diaz, Stephanie M.; Neumann, Colby R.; Jorge, Miguel D.; Sinha, Mithun; Gordillo, Gayle M.; Sen, Chandan K.; Hassanein, Aladdin H.; Surgery, School of MedicinePURPOSE: Lymphedema is limb swelling caused by lymphatic dysfunction. It occurs in 30% of patients that undergo axillary lymph node dissection in the treatment of breast cancer. There is no cure for this disease. Understanding the mechanisms of lymphatic growth will play a pivotal role in developing therapeutic strategies against these conditions. Visualization of lymphangiogenesis and functional assessment remains a challenge. Intravital two-photon microscopy (IVM) is a powerful imaging tool for investigating various biological processes in live animals. Tissue nanotransfection technology (TNT) facilitates a direct, transcutaneous non-viral vector gene delivery using a chip with nanochannel poration in a rapid (<100ms) focused electric field. TNT was used in this study to deliver the genetic cargo in the murine tail lymphedema to assess the lymphangiogenesis. The purpose of this study is to experimentally evaluate the applicability of IVM to visualize and quantify lymphatics. METHODS: The murine tail model of lymphedema was utilized. A 3 mm full thickness skin excision and lymphatic vessel disruption was performed 20 mm from the base of the tail in twelve C57BL/6 mice. TNT was applied to the murine tail (day 0) directly at the surgical site with genetic cargo loaded into the TNT reservoir: Group I (control) was given pCMV6 (expression vector backbone alone) (n=6); Group II had pCMV6-Prox1 (n=6). Post-TNT (day 10), a 3 cm segment of murine tail was deskinned distal to the site of occlusion to optimize visualization. FITC-Dextran (2000 kD) injected intradermally at the distal tail region for lymphatic uptake. Lymphatic vessels are visualized at the second skin excision site with the Leica SP8 Confocal/Multiphoton Microscope and assessed for number of branching points to determine the newly formed lymphatics. Lymphatic vessel density was also observed by immunostaining with anti-Podoplanin antibody. RESULTS: The experimental group II exhibited increased branching points (3-fold) using filamentation analysis compared to control group I at the site of TNT treatment (n=6, p<0.05). Increased lymphatic vessel density was also observed with Podoplanin immunostaining post-TNT application. Intensity quantification of immunohistochemistry revealed greater expression of Podoplanin in Group II when compared to Group I (n=6, p<0.05). CONCLUSION: This study demonstrates a novel, powerful imaging tool for investigating lymphatic vessels in live murine tail model of lymphedema. Intravital microscopy can be utilized for functional assessment of lymphatics and visualization of lymphangiogenesis following gene-based therapy.Item Quantitative 3-dimensional imaging and tissue cytometry reveals lymphatic expansion in acute kidney injury(Elsevier, 2021) Black, Laurence M.; Winfree, Seth; Khochare, Suraj D.; Kamocka, Malgorzata M.; Traylor, Amie M.; Esman, Stephanie K.; Khan, Shehnaz; Zarjou, Abolfazl; Agarwal, Anupam; El-Achkar, Tarek M.; Medicine, School of MedicineThe lymphatic system plays an integral role in physiology and has recently been identified as a key player in disease progression. Tissue injury stimulates lymphatic expansion, or lymphangiogenesis (LA), though its precise role in disease processes remains unclear. LA is associated with inflammation, which is a key component of acute kidney injury (AKI), for which there are no approved therapies. While LA research has gained traction in the last decade, there exists a significant lack of understanding of this process in the kidney. Though innovative studies have elucidated markers and models with which to study LA, the field is still evolving with ways to visualize lymphatics in vivo. Prospero-related homeobox-1 (Prox-1) is the master regulator of LA and determines lymphatic cell fate through its action on vascular endothelial growth factor receptor expression. Here, we investigate the consequences of AKI on the abundance and distribution of lymphatic endothelial cells using Prox1-tdTomato reporter mice (ProxTom) coupled with large-scale three-dimensional quantitative imaging and tissue cytometry (3DTC). Using these technologies, we describe the spatial dynamics of lymphatic vasculature in quiescence and post-AKI. We also describe the use of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) as a marker of lymphatic vessels using 3DTC in the absence of the ProxTom reporter mice as an alternative approach. The use of 3DTC for lymphatic research presents a new avenue with which to study the origin and distribution of renal lymphatic vessels. These findings will enhance our understanding of renal lymphatic function during injury and could inform the development of novel therapeutics for intervention in AKI.Item Topical tissue nanotransfection of Prox1 is effective in the prophylactic management of lymphedema(Elsevier, 2024-01-18) Mohan, Ganesh; Khan, Imran; Neumann, Colby R.; Jorge, Miguel D.; Ahmed, Shahnur; Hulsman, Luci; Sinha, Mithun; Gordillo, Gayle M.; Sen, Chandan K.; Hassanein, Aladdin H.; Surgery, School of MedicineLymphedema is chronic limb swelling resulting from lymphatic dysfunction. There is no cure for the disease. Clinically, a preventive surgical approach called immediate lymphatic reconstruction (ILR) has gained traction. Experimental gene-based therapeutic approaches (e.g., using viral vectors) have had limited translational applicability. Tissue nanotransfection (TNT) technology uses a direct, transcutaneous nonviral vector, gene delivery using a chip with nanochannel poration in response to a rapid (<100 ms) focused electric field. The purpose of this study was to experimentally prevent lymphedema using focal delivery of a specific gene Prox1 (a master regulator of lymphangiogenesis). TNT was applied to the previously optimized lymphedematous mice tail (day 0) directly at the surgical site with genetic cargo loaded into the TNT reservoir: group I (sham) was given pCMV6 (expression vector backbone alone) and group II was treated with pCMV6-Prox1. Group II mice had decreased tail volume (47.8%) compared to sham and greater lymphatic clearance on lymphangiography. Immunohistochemistry showed greater lymphatic vessel density and RNA sequencing exhibited reduced inflammatory markers in group II compared to group I. Prox1 prophylactically delivered using TNT to the surgical site on the day of injury decreased the manifestations of lymphedema in the murine tail model compared to control.Item VEGFR3 tyrosine kinase inhibition aggravates cisplatin nephrotoxicity(American Physiological Society, 2021) Black, Laurence M.; Farrell, Elisa R.; Barwinska, Daria; Osis, Gunars; Zmijewska, Anna A.; Traylor, Amie M.; Esman, Stephanie K.; Bolisetty, Subhashini; Whipple, Grace; Kamocka, Malgorzata M.; Winfree, Seth; Spangler, Daryll R.; Khan, Shehnaz; Zarjou, Abolfazl; El-Achkar, Tarek M.; Agarwal, Anupam; Medicine, School of MedicineExpansion of renal lymphatic networks, or lymphangiogenesis (LA), is well recognized during development and is now being implicated in kidney diseases. Although LA is associated with multiple pathological conditions, very little is known about its role in acute kidney injury. The purpose of this study was to evaluate the role of LA in a model of cisplatin-induced nephrotoxicity. LA is predominately regulated by vascular endothelial growth factor (VEGF)-C and VEGF-D, ligands that exert their function through their cognate receptor VEGF receptor 3 (VEGFR3). We demonstrated that use of MAZ51, a selective VEGFR3 inhibitor, caused significantly worse structural and functional kidney damage in cisplatin nephrotoxicity. Apoptotic cell death and inflammation were also increased in MAZ51-treated animals compared with vehicle-treated animals following cisplatin administration. Notably, MAZ51 caused significant upregulation of intrarenal phospho-NF-κB, phospho-JNK, and IL-6. Cisplatin nephrotoxicity is associated with vascular congestion due to endothelial dysfunction. Using three-dimensional tissue cytometry, a novel approach to explore lymphatics in the kidney, we detected significant vascular autofluorescence attributed to erythrocytes in cisplatin alone-treated animals. Interestingly, no such congestion was detected in MAZ51-treated animals. We found increased renal vascular damage in MAZ51-treated animals, whereby MAZ51 caused a modest decrease in the endothelial markers endomucin and von Willebrand factor, with a modest increase in VEGFR2. Our findings identify a protective role for de novo LA in cisplatin nephrotoxicity and provide a rationale for the development of therapeutic approaches targeting LA. Our study also suggests off-target effects of MAZ51 on the vasculature in the setting of cisplatin nephrotoxicity. NEW & NOTEWORTHY: Little is known about injury-associated LA in the kidney and its role in the pathophysiology of acute kidney injury (AKI). Observed exacerbation of cisplatin-induced AKI after LA inhibition was accompanied by increased medullary damage and cell death in the kidney. LA inhibition also upregulated compensatory expression of LA regulatory proteins, including JNK and NF-κB. These data support the premise that LA is induced during AKI and lymphatic expansion is a protective mechanism in cisplatin nephrotoxicity.