Precursor and interstitial Cajal cells in the human embryo liver

Area of Science:

• Developmental biology
• Hepatology
• Cell biology

Background:

• Interstitial Cajal Cells (ICCs) presence is established in adult human liver, but their immunophenotypes in the human embryonic liver (HEL) are poorly understood.
• A hypothesis suggests ICCs exist in HEL and are distinct from precursor/progenitor cell populations.

Purpose of the Study:

• To investigate the presence and immunophenotypes of cell types, including potential ICCs, in the human embryonic liver.
• To characterize cell populations in the HEL using specific antibody markers.

Main Methods:

• A qualitative study was conducted on five human embryos (23-29 mm).
• Immunohistochemistry was performed using antibodies against CD117/c-kit, CD31, CD34, CD90, CD105, DOG1, Ki67, and adiponectin.

Main Results:

• Blasts and hematopoietic cells were the predominant cell types.
• Interstitial cells with characteristic morphology were found, expressing DOG1 and sparsely CD117/c-kit, leading to their identification as ICCs or telocytes (TCs).
• Blasts were generally CD34-/CD105+, with some CD117/c-kit+ and CD90+ cells. Hematopoietic precursors were Ki67+, and adiponectin was found on blast plasmalemmas. Endothelia were CD31+/CD34+.

Conclusions:

• The study identified Interstitial Cajal Cells (ICCs) and/or telocytes (TCs) in the human embryonic liver, characterized by DOG1 expression.
• Further research is needed to correlate precursor cell types and immunophenotypes during human liver organogenesis.
• Investigation of ICCs/TCs in the human fetal liver is recommended.