Introduction

Abnormal angiogenesis is central to vascular disease and cancer, and noninvasive biomarkers of vascular origin are needed to evaluate patients and therapies. Vascular endothelial growth factor receptors (VEGFRs) are often dysregulated in these diseases, making them promising biomarkers, but the need for an invasive biopsy has limited biomarker research on VEGFRs. Here, we pioneer a blood biopsy approach to quantify VEGFR plasma membrane localization on two circulating vascular proxies: circulating endothelial cells (cECs) and circulating progenitor cells (cPCs).

Methods

Using quantitative flow cytometry, we examined VEGFR expression on cECs and cPCs in four age-sex groups: peri/premenopausal females (aged < 50 years), menopausal/postmenopausal females (≥ 50 years), and younger and older males with the same age cut-off (50 years).

Results

cECs in peri/premenopausal females consisted of two VEGFR populations: VEGFR-low (~ 55% of population: population medians ~ 3000 VEGFR1 and 3000 VEGFR2/cell) and VEGFR-high (~ 45%: 138,000 VEGFR1 and 39,000–236,000 VEGFR2/cell), while the menopausal/postmenopausal group only possessed the VEGFR-low cEC population; and 27% of cECs in males exhibited high plasma membrane VEGFR expression (206,000 VEGFR1 and 155,000 VEGFR2/cell). The absence of VEGFR-high cEC subpopulations in menopausal/postmenopausal females suggests that their high-VEGFR cECs are associated with menstruation and could be noninvasive proxies for studying the intersection of age-sex in angiogenesis. VEGFR1 plasma membrane localization in cPCs was detected only in menopausal/postmenopausal females, suggesting a menopause-specific regenerative mechanism.

Conclusions

Overall, our quantitative, noninvasive approach targeting cECs and cPCs has provided the first insights into how sex and age influence VEGFR plasma membrane localization in vascular cells.

中文翻译：

---

迈向基于血液的精准医学：识别循环血管细胞上的年龄性别特异性血管生物标志物数量

介绍

异常血管生成是血管疾病和癌症的核心，需要血管起源的非侵入性生物标志物来评估患者和治疗。血管内皮生长因子受体 (VEGFR) 在这些疾病中通常失调，这使得它们成为有前途的生物标志物，但对侵入性活检的需求限制了对 VEGFR 的生物标志物研究。在这里，我们开创了一种血液活检方法来量化两个循环血管替代物上的 VEGFR 质膜定位：循环内皮细胞 (cEC) 和循环祖细胞 (cPC)。

方法

使用定量流式细胞术，我们检测了四个年龄性别组中 cEC 和 cPC 上的 VEGFR 表达：围绝经期/绝经前女性（年龄 < 50 岁）、绝经/绝经后女性（≥ 50 岁）以及同龄的年轻和老年男性截止日期（50 年）。

结果

围绝经期/绝经前女性的 cEC 由两个 VEGFR 群体组成：VEGFR 低（~ 55% 群体：群体中位数~ 3000 VEGFR1 和 3000 VEGFR2/细胞）和 VEGFR 高（~ 45%：138,000 VEGFR1 和 39,000–236,000 VEGFR2/细胞），而绝经/绝经后组仅拥有 VEGFR 低的 cEC 群体；男性中 27% 的 cEC 表现出高质膜 VEGFR 表达（206,000 个 VEGFR1 和 155,000 个 VEGFR2/细胞）。绝经/绝经后女性中不存在高 VEGFR cEC 亚群，这表明她们的高 VEGFR cEC 与月经相关，并且可以作为研究血管生成中年龄-性别交叉的无创指标。仅在绝经/绝经后女性中检测到 cPC 中的 VEGFR1 质膜定位，表明更年期特异性的再生机制。

结论

总体而言，我们针对 cEC 和 cPC 的定量、非侵入性方法首次深入了解性别和年龄如何影响血管细胞中 VEGFR 质膜定位。