Estrogen-receptor expression and function in thymocytes in relation to gender and age

Area of Science:

• Immunology
• Endocrinology
• Developmental Biology

Background:

• Estrogen receptor (ER) plays a role in various physiological processes, but its function in thymocyte development concerning gender and age remains incompletely understood.
• Thymocytes are crucial for T-cell maturation, a process influenced by hormonal signaling.

Purpose of the Study:

• To investigate the expression and functional activity of estrogen receptors (ER) in thymocytes across different age groups and genders in mice.
• To explore the impact of estradiol (E2) and dihydrotestosterone (DHT) on thymocyte function and development in relation to age and sex.

Main Methods:

• Western immunoblotting and flow cytometry were used to detect ER expression in thymocytes from young, middle-aged, and old female and male C57BL/6J mice.
• In vivo and in vitro experiments assessed the functional activity of ER by measuring thymic creatine kinase (CK) activity and analyzing thymocyte culture cellularity and phenotypes after hormonal treatments (E2, DHT).

Main Results:

• ER expression was detected in thymocytes of both female and male mice across all age groups.
• While ER appears non-functional in male thymocytes, estradiol (E2) treatment increased thymic creatine kinase (CK) activity in females.
• Estradiol (E2) promoted increased cellularity in co-cultures of young female thymocytes and fetal thymus explants, but not in old females, without altering CD4/CD8 phenotypes.

Conclusions:

• Estrogen receptor (ER) is expressed in mouse thymocytes irrespective of gender and age, but its functionality is sex-dependent, being impaired in males.
• Estradiol (E2) demonstrates age-dependent functional effects on thymocyte development in females, highlighting a significant interplay between ER, gender, age, and T-cell development.