Ramamoorthy Sudhakar, Garg Sumit, Mishra Baijayantimala, Radotra Bishan Dass, Saikia Uma Nahar
Department of Pathology, NRI Medical College, Chinakakani, IND.
Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, IND.
Cureus. 2023 Apr 4;15(4):e37138. doi: 10.7759/cureus.37138. eCollection 2023 Apr.
Coxsackievirus and adenovirus receptor (CAR) homologs have been identified in many species, and their proteins appeared to be highly conserved in evolution. While most of the human studies are about pathological conditions, the animal studies were more about the physiological and developmental functions of receptors. The expression of CAR is developmentally regulated, and its tissue localization is complex. Hence, we planned to study CAR expression in five different human organs at autopsy in different age groups. CAR expression was analyzed in the pituitary, heart, liver, pancreas, and kidney by immunohistochemistry, and CAR mRNA expression in the heart and pituitary by real-time PCR. In the current study, CAR expression was strong in cells of the anterior pituitary, hepatocytes, and bile ducts in the liver, acini, and pancreas and distal convoluted tubule/collecting duct in the kidney, with uniform expression in all age groups. We have noted high CAR expression in fetuses and infantile hearts, which get reduced drastically in adults due to its presumed developmental role in intrauterine life studied in animal models. In addition, the receptor was expressed in glomerular podocytes around the period of fetus viability (37 weeks) but not in early fetuses and adults. We have hypothesized that this intermittent expression could be responsible for the intercellular contact normally formed between the podocytes during the developmental phase. Pancreatic islets also showed increased expression after the emergence of the viability period but not in early fetuses and adults, which might be related to an increase in fetal insulin secretion at that particular age group.
柯萨奇病毒和腺病毒受体（CAR）同系物已在许多物种中被鉴定出来，其蛋白质在进化过程中似乎高度保守。虽然大多数人体研究是关于病理状况的，但动物研究更多是关于受体的生理和发育功能。CAR的表达受发育调控，其组织定位复杂。因此，我们计划在尸检时研究不同年龄组五个不同人体器官中的CAR表达情况。通过免疫组织化学分析垂体、心脏、肝脏、胰腺和肾脏中的CAR表达，并通过实时PCR分析心脏和垂体中的CAR mRNA表达。在当前研究中，CAR在前叶垂体细胞、肝脏中的肝细胞和胆管、胰腺腺泡以及肾脏的远曲小管/集合管中表达强烈，在所有年龄组中表达均一。我们注意到胎儿和婴儿心脏中CAR表达较高，由于在动物模型中研究发现其在子宫内生活中具有假定的发育作用，所以在成年人中CAR表达急剧下降。此外，该受体在胎儿存活期（37周）左右的肾小球足细胞中表达，但在早期胎儿和成年人中不表达。我们推测这种间歇性表达可能是发育阶段足细胞之间正常形成的细胞间接触的原因。胰岛在存活期出现后也显示表达增加，但在早期胎儿和成年人中不增加，这可能与该特定年龄组胎儿胰岛素分泌增加有关。
