Angiocrine Factors in Salivary Gland Regeneration

摘要： 唾液功能减退，或减少唾液流量，是一种常见的条件所造成的自身免疫性 疾病干燥综合征，放射治疗头颈癌，以及副作用 药物治疗唾液功能减退会导致营养、牙齿和心理健康方面的困难， 导致生活质量下降。目前的治疗选择只有姑息和新的再生 需要治疗。再生是在损伤或损害后组织的生长、更新或恢复。 生物体的再生能力各不相同，哺乳动物的再生能力在很大程度上是有限的。研究 再生的下颌下唾液腺，我们将采用导管结扎模型，其中腺 结扎两周后萎缩，由于腺泡细胞死亡导致腺体重量下降， 分泌颗粒丢失。在取出夹子或结扎后，下颌下唾液腺再生， 由于腺泡细胞增殖和分泌颗粒的恢复，腺体重量增加。大多数研究 使用导管结扎模型的研究集中在腺泡细胞的作用，因为它们在产生 然而，排列在血管内表面的内皮细胞对血管再生至关重要。 其他器官。尽管内皮细胞功能障碍与干燥综合征患者的一部分有关， 以及接受放射治疗作为头颈癌治疗的患者， 对唾液腺功能和修复能力的贡献尚不清楚。内皮细胞在血管生成中起关键作用， 器官发育，稳态，通过分泌旁分泌因子再生，包括 生长因子、形态发生素、细胞外基质成分和作用于上皮细胞的趋化因子， 它们统称为血管分泌因子。血管分泌因子信号已被证明是 器官特异性的，在再生期间变化，并随着再生的时间过程而改变。 然而，下颌下腺在体内平衡过程中产生的血管分泌因子， 再生尚未定义。使用导管结扎模型，我将分析产生的血管分泌因子 与结扎两周相比， 外科控制腺体。RNA-seq将用于鉴定由以下物质产生的血管分泌因子靶点： 活跃再生的唾液内皮细胞3天和6天后上皮细胞的微阵列分析 去连接将用于鉴定血管分泌因子受体表达的潜在变化。敲减和 过表达慢病毒构建体将被离体使用以确定这些推定的慢病毒的贡献。 唾液腺类器官中的血管分泌因子，并确定可能的作用机制。定义 再生过程中血管分泌因子的作用机制将使我们更好地理解 可能的手段，为未来的功能恢复的唾液腺。该培训计划还将为 作为一名教授，我的研究和教学生涯。

Abstract: Salivary hypofunction, or reduced saliva flow, is a common condition resulting from the autoimmune disease Sjögren’s Syndrome, radiation therapy for treatment of head and neck cancer, and side effects of medications. Salivary hypofunction can lead to difficulties with nutritional, dental, and psychological health, leading to a decreased quality of life. Current treatment options are only palliative and new regenerative therapies are needed. Regeneration is the growth, renewal, or restoration of tissue following injury or damage. Regenerative ability varies among organisms, with mammalian regeneration being largely limited. To study regeneration of the submandibular salivary gland we will employ a ductal ligation model in which the gland atrophies following a two-week ligation, resulting in a decrease in gland weight due to acinar cell death and loss of secretory granules. After clip removal, or deligation, the submandibular salivary gland regenerates, increasing in gland weight, due to acinar cell proliferation and restoration of secretory granules. Most studies using the ductal ligation model have focused on the role of the acinar cells due to their importance in producing saliva; however, endothelial cells that line the interior surface of blood vessels are critical for regeneration of other organs. Although endothelial cell dysfunction has been linked to a subset of Sjögren’s Syndrome patients as well as patients receiving radiation therapy as a treatment for head and neck cancer, how endothelial cells contribute to salivary gland function and repair capacity is not understood. Endothelial cells play critical roles in organ development, homeostasis, and regeneration through the secretion of paracrine factors, including growth factors, morphogens, extracellular matrix components, and chemokines that act on epithelial cells, which are collectively referred to as angiocrine factors. Angiocrine factor signaling has been shown to be organ-specific, to vary during times of regeneration, and to change over the time course of regeneration. However, angiocrine factors produced by the submandibular salivary gland during homeostasis and regeneration have not been defined. Using the ductal ligation model, I will profile angiocrine factors produced by endothelial cells after three and six days of deligation in comparison to two weeks of ligation relative to surgical control glands. RNA-seq will be used to identify the angiocrine factor targets that are produced by actively regenerating salivary endothelial cells. Microarray analysis of epithelial cells after three and six days deligation will be used to identify potential changes in angiocrine factor receptor expression. Knockdown and overexpression lentiviral constructs will be used ex vivo to determine the contribution of these putative angiocrine factors in salivary gland organoids and to identify possible mechanisms of action. Defining the mechanism of action of the angiocrine factors during regeneration will allow for a better understanding of possible means for future functional restoration of the salivary gland. This training program will also prepare me for a career in research and teaching as a professor.