Banki Eszter, Sosnowska Danuta, Tucsek Zsuzsanna, Gautam Tripti, Toth Peter, Tarantini Stefano, Tamas Andrea, Helyes Zsuzsanna, Reglodi Dora, Sonntag William E, Csiszar Anna, Ungvari Zoltan
Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center. Department of Anatomy, MTA-PTE PACAP Lendulet Research Team.
Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center.
J Gerontol A Biol Sci Med Sci. 2015 Jun;70(6):665-74. doi: 10.1093/gerona/glu116. Epub 2014 Aug 18.
Aging impairs angiogenic capacity of cerebromicrovascular endothelial cells (CMVECs) promoting microvascular rarefaction, but the underlying mechanisms remain elusive. PACAP is an evolutionarily conserved neuropeptide secreted by endothelial cells and neurons, which confers important antiaging effects. To test the hypothesis that age-related changes in autocrine PACAP signaling contributes to dysregulation of endothelial angiogenic capacity, primary CMVECs were isolated from 3-month-old (young) and 24-month-old (aged) Fischer 344 x Brown Norway rats. In aged CMVECs, expression of PACAP was decreased, which was associated with impaired capacity to form capillary-like structures, impaired adhesiveness to collagen (assessed using electric cell-substrate impedance sensing [ECIS] technology), and increased apoptosis (caspase3 activity) when compared with young cells. Overexpression of PACAP in aged CMVECs resulted in increased formation of capillary-like structures, whereas it did not affect cell adhesion. Treatment with recombinant PACAP also significantly increased endothelial tube formation and inhibited apoptosis in aged CMVECs. In young CMVECs shRNA knockdown of autocrine PACAP expression significantly impaired tube formation capacity, mimicking the aging phenotype. Cellular and mitochondrial reactive oxygen species production (dihydroethidium and MitoSox fluorescence, respectively) were increased in aged CMVECs and were unaffected by PACAP. Collectively, PACAP exerts proangiogenic effects and age-related dysregulation of autocrine PACAP signaling may contribute to impaired angiogenic capacity of CMVECs in aging.
衰老会损害脑微血管内皮细胞（CMVECs）的血管生成能力，促进微血管稀疏，但其潜在机制仍不清楚。垂体腺苷酸环化酶激活肽（PACAP）是一种由内皮细胞和神经元分泌的进化上保守的神经肽，具有重要的抗衰老作用。为了验证自分泌PACAP信号的年龄相关变化导致内皮血管生成能力失调这一假设，从3个月大（年轻）和24个月大（老龄）的Fischer 344×Brown Norway大鼠中分离出原代CMVECs。在老龄CMVECs中，PACAP的表达降低，这与形成毛细血管样结构的能力受损、对胶原蛋白的粘附性受损（使用细胞-基质阻抗传感[ECIS]技术评估）以及与年轻细胞相比凋亡增加（半胱天冬酶3活性）有关。在老龄CMVECs中过表达PACAP导致毛细血管样结构的形成增加，而对细胞粘附没有影响。用重组PACAP处理也显著增加了老龄CMVECs中的内皮管形成并抑制了凋亡。在年轻CMVECs中，自分泌PACAP表达的短发夹RNA（shRNA）敲低显著损害了管形成能力，模拟了衰老表型。老龄CMVECs中的细胞和线粒体活性氧产生（分别为二氢乙锭和MitoSox荧光）增加，且不受PACAP影响。总的来说，PACAP发挥促血管生成作用，自分泌PACAP信号的年龄相关失调可能导致衰老过程中CMVECs血管生成能力受损。
