Department of Pharmaceutical Sciences, College of Health Professions, North Dakota State University, Fargo, ND, 58108, USA.
Museum District Eye Center, Houston, TX, USA.
Eur J Pharmacol. 2022 Apr 5;920:174842. doi: 10.1016/j.ejphar.2022.174842. Epub 2022 Feb 23.
Aging with diabetes is associated with impaired vasoprotective functions and decreased nitric oxide (NO) generation in CD34 cells. Transforming growth factor- β1 (TGF-β1) is known to regulate hematopoietic functions. This study tested the hypothesis that transforming growth factor- β1 (TGF-β1) is upregulated in diabetic CD34 cells and impairs NO generation via thrombospondin-1 (TSP-1)/CD47/NO pathway. CD34 cells from nondiabetic (ND) (n=58) or diabetic older adults (DB) (both type 1 and type 2) (n=62) were isolated from peripheral blood. TGF-β1 was silenced by using an antisense delivered as phosphorodiamidate morpholino oligomer (PMO-TGF-β1). Migration and proliferation in response to stromal-derived factor-1α (SDF-1α) were evaluated. NO generation and eNOS phosphorylation were determined by flow cytometry. CD34 cells from older, but not younger, diabetics have higher expression of TGF-β1 compared to that observed in cells derived from healthy individuals (P<0.05, n=14). TSP-1 expression was higher (n=11) in DB compared to ND cells. TGFβ1-PMO decreased the secretion of TGF-β1, which was accompanied with decreased TSP-1 expression. Impaired proliferation, migration and NO generation in response to SDF-1α in DB cells were reversed by TGF-β1-PMO (n=6). TSP-1 inhibited migration and proliferation of nondiabetic CD34 cells that was reversed by CD47-siRNA, which also restored these responses in diabetic CD34 cells. TSP-1 opposed SDF-1α-induced eNOS phosphorylation at Ser that was reversed by CD47-siRNA. These results infer that increased TGF-β1 expression in CD34 cells induces dysfunction in CD34 cells from diabetic older adults via TSP-1/CD47-dependent inhibition of NO generation.
糖尿病患者随着年龄的增长，其血管保护功能受损，CD34 细胞中一氧化氮（NO）的生成减少。转化生长因子-β1（TGF-β1）已知可调节造血功能。本研究检验了这样一个假设，即在糖尿病 CD34 细胞中 TGF-β1 上调，并通过血小板反应蛋白-1（TSP-1）/CD47/NO 途径抑制 NO 生成。从非糖尿病（ND）（n=58）或老年糖尿病（DB）（1 型和 2 型）（n=62）的外周血中分离 CD34 细胞。使用作为磷酰胺二酯吗啉代寡聚物（PMO-TGF-β1）传递的反义寡核苷酸来沉默 TGF-β1。评估对基质衍生因子-1α（SDF-1α）的迁移和增殖反应。通过流式细胞术测定 NO 生成和 eNOS 磷酸化。与来自健康个体的细胞相比，来自较年长但非年轻糖尿病患者的 CD34 细胞具有更高的 TGF-β1 表达（P<0.05，n=14）。与 ND 细胞相比，DB 细胞中的 TSP-1 表达更高（n=11）。TGFβ1-PMO 降低了 TGF-β1 的分泌，同时伴有 TSP-1 表达的降低。DB 细胞中对 SDF-1α的增殖、迁移和 NO 生成受损反应被 TGF-β1-PMO 逆转（n=6）。TSP-1 抑制非糖尿病 CD34 细胞的迁移和增殖，该抑制作用被 CD47-siRNA 逆转，这也恢复了糖尿病 CD34 细胞的这些反应。TSP-1 拮抗 SDF-1α诱导的 Ser 上的 eNOS 磷酸化，该拮抗作用被 CD47-siRNA 逆转。这些结果推断，CD34 细胞中 TGF-β1 表达的增加通过 TSP-1/CD47 依赖性抑制 NO 生成诱导老年糖尿病患者 CD34 细胞功能障碍。
