PDF(Pubmed)
Abstract：
UNASSIGNED: Abnormalities in aquaporins are implicated in the pathological progression of dry eye syndrome. Retinoic acid (RA) regulates cellular proliferation, differentiation, and apoptosis in the cornea, thereby being associated with dry eye disease (DED). The objective of this study is to explore the underlying mechanisms responsible for RA metabolic abnormalities in corneas lacking aquaporin 5 (AQP5).
UNASSIGNED: Dry eye (DE) models were induced via subcutaneous scopolamine hydrobromide. Aqp5 knockout (Aqp5-/-) mice and DE mice were utilized to assess corneal epithelial alterations. Tear secretion, goblet cell counts, and corneal punctate defects were evaluated. The impact of Aqp5 on RA-related enzymes and receptors was investigated using pharmacological RA or SR (A JunB inhibitor), a transcription factor JunB inhibitor, treatment in mouse corneal epithelial cells (CECs), or human corneal epithelial cells (HCECs). The HCECs and NaCl-treated HCECs underwent quantitative real-time PCR (qRT-PCR), immunofluorescent, Western blot, and TUNEL assays. The regulation of transcription factor JunB on Aldh1a1 was explored via ChIP-PCR.
UNASSIGNED: Aqp5 and Aldh1a1 were reduced in both CECs of DE mice and NaCl-induced HCECs. Aqp5-/- mice exhibited DE phenotype and reduced Aldh1a1. RA treatment reduced apoptosis, promoted proliferation, and improved the DE phenotype in Aqp5-/- mice. JunB enrichment in the Aldh1a1 promoter was identified by ChIP-PCR. SR significantly increased Aldh1a1 expression, Ki67, and ΔNp63-positive cells, and decreased TUNEL-positive cells in CECs and HCECs.
UNASSIGNED: Our findings demonstrated the downregulation of Aqp5 expression and aberrant RA metabolism in DE conditions. Knockout of Aqp5 resulted in reduced production of RA through activation of JunB, subsequently leading to the manifestation of DE symptoms.
UNASSIGNED: Dry eye (DE) models were induced via subcutaneous scopolamine hydrobromide. Aqp5 knockout (Aqp5-/-) mice and DE mice were utilized to assess corneal epithelial alterations. Tear secretion, goblet cell counts, and corneal punctate defects were evaluated. The impact of Aqp5 on RA-related enzymes and receptors was investigated using pharmacological RA or SR (A JunB inhibitor), a transcription factor JunB inhibitor, treatment in mouse corneal epithelial cells (CECs), or human corneal epithelial cells (HCECs). The HCECs and NaCl-treated HCECs underwent quantitative real-time PCR (qRT-PCR), immunofluorescent, Western blot, and TUNEL assays. The regulation of transcription factor JunB on Aldh1a1 was explored via ChIP-PCR.
UNASSIGNED: Aqp5 and Aldh1a1 were reduced in both CECs of DE mice and NaCl-induced HCECs. Aqp5-/- mice exhibited DE phenotype and reduced Aldh1a1. RA treatment reduced apoptosis, promoted proliferation, and improved the DE phenotype in Aqp5-/- mice. JunB enrichment in the Aldh1a1 promoter was identified by ChIP-PCR. SR significantly increased Aldh1a1 expression, Ki67, and ΔNp63-positive cells, and decreased TUNEL-positive cells in CECs and HCECs.
UNASSIGNED: Our findings demonstrated the downregulation of Aqp5 expression and aberrant RA metabolism in DE conditions. Knockout of Aqp5 resulted in reduced production of RA through activation of JunB, subsequently leading to the manifestation of DE symptoms.
摘要：
■水通道蛋白的异常与干眼综合征的病理进展有关。维甲酸（RA）调节细胞增殖，分化,和角膜中的细胞凋亡，从而与干眼病(DED)相关。这项研究的目的是探索缺乏水通道蛋白5（AQP5）的角膜中RA代谢异常的潜在机制。
■通过皮下氢溴酸东莨菪碱诱导干眼(DE)模型。利用Aqp5敲除(Aqp5-/-)小鼠和DE小鼠来评估角膜上皮改变。泪液分泌,杯状细胞计数,并对角膜点状缺损进行评价。使用药理学RA或SR（JunB抑制剂）研究了Aqp5对RA相关酶和受体的影响，转录因子JunB抑制剂，小鼠角膜上皮细胞（CEC）的治疗，或人类角膜上皮细胞（HCECs）。HCECs和NaCl处理的HCECs进行了定量实时PCR（qRT-PCR），免疫荧光，蛋白质印迹,和TUNEL检测。通过ChIP-PCR探索转录因子JunB对Aldh1a1的调控。
■Aqp5和Aldh1a1在DE小鼠的CEC和NaCl诱导的HCECs中均降低。Aqp5-/-小鼠表现出DE表型和降低的Aldh1a1。RA治疗减少细胞凋亡，促进扩散，并改善了Aqp5-/-小鼠的DE表型。通过ChIP-PCR鉴定Aldh1a1启动子中的JunB富集。SR显著增加Aldh1a1表达，Ki67和ΔNp63阳性细胞，CECs和HCECs中TUNEL阳性细胞减少。
■我们的发现证明了在DE条件下Aqp5表达下调和RA代谢异常。敲除Aqp5导致通过激活JunB减少RA的产生，随后导致DE症状的表现。
■通过皮下氢溴酸东莨菪碱诱导干眼(DE)模型。利用Aqp5敲除(Aqp5-/-)小鼠和DE小鼠来评估角膜上皮改变。泪液分泌,杯状细胞计数,并对角膜点状缺损进行评价。使用药理学RA或SR（JunB抑制剂）研究了Aqp5对RA相关酶和受体的影响，转录因子JunB抑制剂，小鼠角膜上皮细胞（CEC）的治疗，或人类角膜上皮细胞（HCECs）。HCECs和NaCl处理的HCECs进行了定量实时PCR（qRT-PCR），免疫荧光，蛋白质印迹,和TUNEL检测。通过ChIP-PCR探索转录因子JunB对Aldh1a1的调控。
■Aqp5和Aldh1a1在DE小鼠的CEC和NaCl诱导的HCECs中均降低。Aqp5-/-小鼠表现出DE表型和降低的Aldh1a1。RA治疗减少细胞凋亡，促进扩散，并改善了Aqp5-/-小鼠的DE表型。通过ChIP-PCR鉴定Aldh1a1启动子中的JunB富集。SR显著增加Aldh1a1表达，Ki67和ΔNp63阳性细胞，CECs和HCECs中TUNEL阳性细胞减少。
■我们的发现证明了在DE条件下Aqp5表达下调和RA代谢异常。敲除Aqp5导致通过激活JunB减少RA的产生，随后导致DE症状的表现。
