MiR-378b Modulates Chlamydia-Induced Upper Genital Tract Pathology

Area of Science:

• Reproductive immunology
• Infectious disease pathology
• Molecular biology

Background:

• Genital Chlamydia trachomatis infection leads to severe reproductive issues like infertility.
• MicroRNAs (miRNAs) are key regulators in host responses to infections, including Chlamydia.
• miR-378b is differentially expressed during Chlamydia infection and reinfection.

Purpose of the Study:

• To investigate the role of miR-378b in the pathological outcomes of Chlamydia infection.
• To determine if miR-378b influences Chlamydia infectivity, replication, and associated reproductive pathologies.

Main Methods:

• Generation of miR-378b knockout mice (miR-378b-/-) using CRISPR/Cas9.
• Infection of miR-378b-/- and wild-type (WT) mice with Chlamydia trachomatis.
• Comparison of Chlamydia burden, reproductive pathologies, and fertility rates between knockout and WT groups.

Main Results:

• miR-378b-/- mice showed impaired Chlamydia clearance and higher bacterial burden compared to WT mice.
• Despite increased Chlamydia burden, miR-378b-/- mice exhibited significantly reduced uterine lesions and dilatations.
• Infected miR-378b-/- mice demonstrated protection from Chlamydia-induced infertility, with fertility rates comparable to uninfected WT mice.

Conclusions:

• miR-378b plays a dual role in Chlamydia infection, regulating both pathogen control and inflammation-driven pathology.
• Absence of miR-378b exacerbates Chlamydia replication but mitigates reproductive complications and infertility.
• These findings suggest miR-378b as a potential biomarker for Chlamydia complications and a target for therapeutic intervention.