Extracellular Vesicles from Adipose Tissue-Derived Stromal Cells Stimulate Angiogenesis in a Scaffold-Dependent Fashion.

BACKGROUND: The extracellular vesicles (EVs) secreted by adipose tissue-derived stromal cells (ASC) are microenvironment modulators in tissue regeneration by releasing their molecular cargo, including miRNAs. However, the influence of ASC-derived extracellular vesicles (ASC-EVs) on endothelial cells (ECs) and vascularisation is poorly understood. The present study aimed to determine the pro-angiogenic effects of ASC-EVs and explore their miRNA profile. METHODS: EVs were isolated from normoxic and hypoxic cultured ASC conditioned culture medium. The miRNA expression profile was determined by miRseq, and EV markers were determined by Western blot and immunofluorescence staining. The uptake dynamics of fluorescently labelled EVs were monitored for 24 h. ASC-EVs' pro-angiogenic effect was assessed by sprouting ex vivo rat aorta rings in left ventricular-decellularized extracellular matrix (LV dECM) hydrogel or basement membrane hydrogel (Geltrex®). RESULTS: ASC-EVs augmented vascular network formation by aorta rings. The vascular network topology and stability were influenced in a hydrogel scaffold-dependent fashion. The ASC-EVs were enriched for several miRNA families/clusters, including Let-7 and miR-23/27/24. The miRNA-1290 was the highest enriched non-clustered miRNA, accounting for almost 20% of all reads in hypoxia EVs. CONCLUSION: Our study revealed that ASC-EVs augment in vitro and ex vivo vascularisation, likely due to the enriched pro-angiogenic miRNAs in EVs, particularly miR-1290. Our results show promise for regenerative and revascularisation therapies based on ASC-EV-loaded ECM hydrogels.

Angiogenesis is promoted by hypoxic cervical carcinoma-derived extracellular vesicles depending on the endothelial cell environment.

INTRODUCTION: Cancer needs perfusion for its growth and metastasis. Cancer cell-derived extracellular vesicles (CA-EVs) alter the tumor microenvironment (TME), potentially promoting angiogenesis. We hypothesize that conditions in the tumor, e.g., hypoxia, and in the target cells of the TME, e.g., nutrient deprivation or extracellular matrix, can affect the angiogenic potential of CA-EVs, which would contribute to explaining the regulation of tumor vascularization and its influence on cancer growth and metastasis. METHODS: CA-EVs were isolated and characterized from cervical carcinoma cell lines HeLa and SiHa cultured under normoxia and hypoxia, and their angiogenic potential was evaluated in vitro in three endothelial cells (ECs) lines and aortic rings, cultured in basal (growth factor-reduced) or complete medium. RESULTS: Hypoxia increased EV production 10-100 times and protein content 2-4 times compared to normoxic CA-EVs. HeLa-EVs contained six times more RNA than SiHa-EVs, and this concentration was not affected by hypoxia. Treatment with CA-EVs increased tube formation and sprouting in ECs and aortic rings cultured in basal medium and long-term stabilized the stablished vascular networks formed by ECs cultured in complete medium. CONCLUSION: Hypoxia differentially affects CA-EVs in a cell line-dependent manner. The cellular environment (nutrient availability and extracellular matrix scaffold) influences the effect of CA-EV on the angiogenic potential of ECs.

[Cutaneous granulomatous reactions at botulinum neurotoxin A injection sites: First manifestation of systemic sarcoidosis]. / Granulomatöse Hautveränderungen an Botulinumtoxin-A-Injektionsstellen : Erstmanifestation einer systemischen Sarkoidose.

CASE REPORT: We report a case of granulomatous skin reaction after injection of an unknown botulinum neurotoxin (BoNT) A preparation. Four years after occurrence of skin lesions, systemic sarcoidosis became manifest. CONCLUSION: In addition to injection trauma, the BoNT A preparation may have acted as an immunogenic stimulus leading to cutaneous manifestation of sarcoidosis.

Skin metastases in metastatic uveal melanoma: GNAQ/GNA11 mutational analysis as a valuable tool.

BACKGROUND: Uveal melanomas represent 3.1% of all melanomas, with a high potential of metastatic disease of up to 50%, where the median survival time is 6 months. Though liver metastases dominate as the primary site for metastasis, the existence of primary skin metastases is still under discussion but has been reported in only a few studies. OBJECTIVES: We present two cases in which patients with a known history of uveal melanoma developed melanoma skin metastases. METHODS: Mutational analysis was performed to clarify the origin of the metastases (uvea or skin). RESULTS: The analyses revealed GNA11 mutations, which are typical for uveal melanoma. These cases strongly suggest the skin to be the primary site of uveal melanoma. CONCLUSIONS: Knowledge about the mutational status of uveal melanomas opens the opportunity for future targeted therapies that directly interact with the mutation and its activated signal cascades. First trials in uveal melanoma have shown promising results with MEK inhibitors.