Allawi Noor, Abdullah Bashar
Department of Oral Diagnosis College of Dentistry/University of Baghdad Baghdad Iraq.
Health Sci Rep. 2022 Jul 20;5(4):e737. doi: 10.1002/hsr2.737. eCollection 2022 Jul.
The involvement of maxillofacial tissues in SARS-CoV-2 infections ranges from mild dysgeusia to life-threatening tissue necrosis, as seen in SARS-CoV-2-associated mucormycosis. Angiotensin-converting enzyme 2 (ACE2) which functions as a receptor for SARS-CoV-2 was reported in the epithelial surfaces of the oral and nasal cavities; however, a complete understanding of the expression patterns in deep oral and maxillofacial tissues is still lacking.
The immunohistochemical expression of ACE2 was analyzed in 95 specimens from maxillofacial tissues and 10 specimens of pulmonary alveolar tissue using a semiquantitative immunohistochemical scoring procedure, taking into account all superficial and deep maxillofacial tissue cells. We also explored the associations of age, gender, and anatomical site with expression scores.
ACE2 was detected in keratinized epithelia (57.34%), non-keratinized epithelia (46.51%), nasal respiratory epithelial cells (73.35%), pulmonary alveolar cells (82.54%), fibroblasts (63.69%), vascular endothelial cells (58.43%), mucous acinar cells (59.88%), serous acinar cells (79.49%), salivary duct cells (86.26%) skeletal muscle fibers (71.01%), neuron support cells (94.25%), and bone marrow cells (72.65%). Age and gender did not affect the expression levels significantly in epithelial cells ( = 0.76, and = 0.7 respectively); however, identical cells expressed different protein levels depending on the site from which the specimens were obtained. For example, dorsal tongue epithelia expressed significantly lower ACE2 scores than alveolar epithelia ( < 0.001). A positive correlation was found between ACE2 expression in fibroblasts and epithelial cells ( = 0.378, = 0.001), and between vascular endothelial and epithelial cells ( = 0.395, = 0.001).
ACE2 is expressed by epithelial cells and subepithelial tissues including fibroblasts, vascular endothelia, skeletal muscles, peripheral nerves, and bone marrow. No correlation was detected between ACE2 expression and patient age or sex while the epithelial expression scores were correlated with stromal scores.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染累及颌面部组织的情况多样，从轻度味觉障碍到危及生命的组织坏死，如在SARS-CoV-2相关毛霉菌病中所见。据报道，作为SARS-CoV-2受体的血管紧张素转换酶2（ACE2）存在于口腔和鼻腔的上皮表面；然而，对于口腔深部和颌面部组织中的表达模式仍缺乏全面了解。
采用半定量免疫组织化学评分程序，对95例颌面部组织标本和10例肺泡组织标本中的ACE2免疫组织化学表达进行分析，涵盖所有颌面部浅表和深部组织细胞。我们还探讨了年龄、性别和解剖部位与表达评分的相关性。
在角化上皮（57.34%）、非角化上皮（46.51%）、鼻呼吸上皮细胞（73.35%）、肺泡细胞（82.54%）、成纤维细胞（63.69%）、血管内皮细胞（58.43%）、黏液腺泡细胞（59.88%）、浆液腺泡细胞（79.49%）、涎腺导管细胞（86.26%）、骨骼肌纤维（71.01%）、神经支持细胞（94.25%）和骨髓细胞（72.65%）中检测到ACE2。年龄和性别对上皮细胞中的表达水平无显著影响（分别为=0.76和=0.7）；然而，相同的细胞根据标本获取部位的不同表达不同水平的蛋白质。例如，舌背上皮的ACE2评分显著低于肺泡上皮（<0.001）。成纤维细胞与上皮细胞中的ACE2表达之间存在正相关（=0.378，=0.001），血管内皮细胞与上皮细胞之间也存在正相关（=0.395，=0.001）。
ACE2由上皮细胞和上皮下组织表达，包括成纤维细胞、血管内皮细胞、骨骼肌、周围神经和骨髓。ACE2表达与患者年龄或性别之间未检测到相关性，而上皮表达评分与基质评分相关。
