Embryonic Stem Cell-Like Subpopulations in Venous Malformation

Abstract

BackgroundVenous malformation (VM) consists of a network of ectatic anomalous thin-walled venous channels. A role for an activating TIE2 mutation in the development of the dilated luminal vessels in VM, and its proposed involvement of embryonic stem cells (ESCs), led us to investigate the expression of ESC markers in subcutaneous VM (SCVM) and intramuscular VM (IMVM).MethodsFormalin-fixed paraffin-embedded sections of SCVM from seven patients and IMVM samples from seven patients were analyzed for the expression of Nanog, pSTAT3, OCT4, SOX2, SALL4, and CD44, using 3,3′-diaminobenzidine (DAB) immunohistochemical (IHC) staining. All these samples did not express lymphatic marker D2-40. NanoString mRNA analysis and RT-PCR were performed on snap-frozen samples of SCVM (n = 3) and IMVM (n = 3) from the respective original cohorts of patients included in DAB IHC staining. To confirm co-expression of two proteins, immunofluorescent (IF) IHC staining on two representative samples of IMVM and SCVM samples from the original cohorts of patients included for DAB IHC staining was performed.ResultsDAB IHC staining demonstrated expression of all of the above ESC markers in both SCVM and IMVM samples. IF IHC staining showed that these markers were localized to the endothelium within these lesions and that Nanog, pSTAT3, SOX2, and CD44 were also expressed by cells outside of the endothelium. NanoString mRNA analysis confirmed transcription activation of pSTAT3, OCT4, and CD44. RT-qPCR confirmed transcription activation of Nanog, SOX2, and SALL4.ConclusionOur findings support the presence of two ESC-like subpopulations, one within and one outside of the endothelium, of both SCVM and IMVM. Given that the endothelial ESC-like subpopulation expresses the more primitive marker, OCT4, it is exciting to speculate that they give rise to the non-endothelial subpopulation.

Expression of Embryonic Stem Cell Markers in Microcystic Lymphatic Malformation

“…Similar findings in VM 14 and those in mLM presented in this report suggest that this putative ESC-like population within both types of vascular malformations may be central to their development, although larger studies including in vitro and in vivo investigations are needed to confirm these results.…”

“…We have recently demonstrated an embryonic stem cell (ESC)-like population on the endothelium of the lesional vessels as well as cells within the stroma, in subcutaneous and intramuscular venous malformation (VM). 14 ESCs are characterized by pluripotency and self-renewal. The search for markers of ESCs started with the isolation of cells from the inner cell mass of human blastocysts.…”

Embryonic Stem Cell-like Population within Venous Malformation Expresses the Renin–Angiotensin System

“…Venous malformation (VM) consists of a network of thin-walled ectatic venous channels with deficient media, 1 and TIE2 and PIK3CA mutations have been demonstrated. 2 Management of VM remains unsatisfactory. 2…”

“…There are 2 embryonic stem cell (ESC)-like subpopulations within subcutaneous VM (SCVM) and intramuscular VM (IMVM): one on the endothelium expressing the ESC markers NANOG, pSTAT3, OCT4, SOX2, SALL4, and CD44; and another outside the endothelium expressing NANOG, pSTAT3, SOX2, and CD44. 2 Both SCVM and IMVM express components of the renin–angiotensin system (RAS). 1 This study investigated whether the primitive subpopulations within SCVM and IMVM express the RAS.…”

“…Four-micrometer-thick formalin-fixed paraffin-embedded sections of 2 representative samples each from 7 SCVM (mean age 22.9 years) and 7 IMVM (mean age 21.1 years) patients included in our previous studies, 1,2 underwent immunofluorescence (IF) immunohistochemical (IHC) staining with primary antibodies OCT4 (1:30; cat#MRQ-10, Cell Marque, Santa Cruz, Calif.), SOX2 (1:200, cat#PA1-094, Thermo Fisher Scientific, Waltham, Mass. ), (pro)renin receptor (PRR) (1:2000; cat#AB40790, Abcam, Cambridge, Mass.…”