Yoshino K, Garg R, Monroy D, Ji Z, Pflugfelder S C
Ocular Surface and Tear Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL 33136, USA.
Curr Eye Res. 1996 Jun;15(6):615-24. doi: 10.3109/02713689609008901.
Transforming growth factor beta (TGF-beta) isoforms 1 and 2 have recently been detected in stimulated human tear fluid. The purpose of this study was to determine if these TGF-sbeta are produced and secreted by the lacrimal gland.
To accomplish this, reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect expression of TGF-beta1 and TGF-beta2 mRNAs in normal human and rabbit lacrimal gland biopsies. Northern blot analyses were used for comparing the relative levels of expression of these TGF-beta mRNAs in rabbit lacrimal glands. Human lacrimal gland biopsies were evaluated by immunohistochemistry for production of TGF-beta1, TGF-beta1 latency associated peptide (LAP), and TGF-beta2 proteins. Supernatants of unstimulated and carbachol-stimulated human lacrimal gland explant cultures were evaluated for secretion of TGF-beta1 and TGF-beta2 by ELISA:
TGF-beta1 and TGF-beta2 mRNA expression was found in all human and rabbit lacrimal gland specimens by RT-PCR. A greater level of expression of TGF-beta1 than TGF-beta2 mRNA in the rabbit lacrimal gland was noted by Northern blot. In human lacrimal gland biopsies, TGF-beta1 and TGF-beta1 LAP were detected in acinar and ductal epithelia by immunohistochemistry. TGF-beta2 specific antibodies stained a small percentage of acinar and ductal epithelia, as well as material within the lumens of tubulo-acinar complexes in one-third of these glands. TGF-beta1 was detected in supernatants of human lacrimal gland explants, and the concentration of TGF-beta1 increased by an average of 280% after carbachol-stimulation (p = 0.004). TGF-beta2 could not be detected in unstimulated or stimulated human lacrimal gland supernatants.
The results of these experiments indicate that TGF-beta1 and TGF-beta2 are produced by and TGF-beta1 is secreted by the human lacrimal gland. They also suggest that the lacrimal gland may be one source of TGF-beta in human tear fluid.
近期在刺激后的人泪液中检测到转化生长因子β（TGF-β）亚型1和2。本研究的目的是确定这些TGF-β是否由泪腺产生和分泌。
为实现这一目的，采用逆转录聚合酶链反应（RT-PCR）检测正常人及兔泪腺活检组织中TGF-β1和TGF-β2 mRNA的表达。采用Northern印迹分析比较兔泪腺中这些TGF-β mRNA的相对表达水平。通过免疫组织化学评估人泪腺活检组织中TGF-β1、TGF-β1潜伏相关肽（LAP）和TGF-β2蛋白的产生情况。通过酶联免疫吸附测定（ELISA）评估未刺激和卡巴胆碱刺激的人泪腺外植体培养物上清液中TGF-β1和TGF-β2的分泌情况。
通过RT-PCR在所有人和兔泪腺标本中均发现了TGF-β1和TGF-β2 mRNA表达。Northern印迹显示兔泪腺中TGF-β1 mRNA的表达水平高于TGF-β2 mRNA。在人泪腺活检组织中，通过免疫组织化学在腺泡和导管上皮中检测到TGF-β1和TGF-β1 LAP。TGF-β2特异性抗体在一小部分腺泡和导管上皮以及三分之一的这些腺体的小管-腺泡复合体管腔内的物质中染色。在人泪腺外植体的上清液中检测到TGF-β1，卡巴胆碱刺激后TGF-β1的浓度平均增加280%（p = 0.004）。在未刺激或刺激的人泪腺上清液中未检测到TGF-β2。
这些实验结果表明，TGF-β1和TGF-β2由人泪腺产生，且TGF-β1由人泪腺分泌。它们还提示泪腺可能是人泪液中TGF-β的来源之一。
