title: Extrahepatic and intrahepatic human portal interstitial Cajal cells.
abstract: Portal interstitial cells of Cajal (PICCs), acting as vascular pacemakers, were previously only identified in nonhumans. Moreover, there is no evidence available about the presence of such cells within the liver. The objective of the study is to evaluate whether or not PICCs are identifiable in humans and, if they are, whether or not they are following the scaffold of portal vein (PV) branches within the liver. We obtained extrahepatic PVs and liver samples from six adult human cadavers, negative for liver disease, in accordance with ethical rules. They were stained with hematoxylin-eosin (HE) and Giemsa, and then we performed immunohistochemistry on formalin-fixed paraffin-embedded specimens for CD117/c-kit, a marker of the Cajal's cells. Immune labeling was also performed for S-100 protein, desmin, glial fibrillary acidic protein (GFAP), neurofilaments, α-smooth muscle actin (α-SMA), and CD34. c-kit-Positive PICCs were identified within the extrahepatic PV, in portal spaces, and septa. On adjacent sections, these PICCs were negative for all the other antibodies used. In conclusion, our study confirms the presence of extrahepatic PICCs on humans, which may act as a possible intrinsic pacemaker in the human PV. However, the intrahepatic PICCs, which were evidenced here for the first time, are in need for further experimental studies to evaluate their functional role. A promising further direction of the study is the PICCs role in the idiopathic portal hypertension.
authors.affiliation: Discipline of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania. anatomon@gmail.com
authors.forename: M C
authors.initials: MC
authors.lastname: Rusu
authors.forename: F
authors.initials: F
authors.lastname: Pop
authors.forename: S
authors.initials: S
authors.lastname: Hostiuc
authors.forename: G C
authors.initials: GC
authors.lastname: Curcă
authors.forename: A
authors.initials: A
authors.lastname: Streinu-Cercel
mesh_terms: D000199:Actins / Q000032:analysis; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002102:Cadaver; D003893:Desmin / Q000032:analysis; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D056885:Interstitial Cells of Cajal / Q000737:chemistry; D008099:Liver / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000032:analysis; D011169:Portal Vein / Q000737:chemistry / Q000166:cytology*; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis; D013194:Staining and Labeling
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D018952:Antigens, CD34; D015415:Biomarkers; D003893:Desmin; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; D009418:S100 Proteins; D019009:Proto-Oncogene Proteins c-kit