Cytokine-induced expression of nitric oxide synthases in Chlamydia trachomatis-infected spontaneous aborters

Abstract

Purpose: The aim of study was to evaluate expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) in Chlamydia trachomatis (CT)-infected spontaneous aborters (SA).

Materials and methods: Endometrial curettage tissue was collected from 140 SA (sporadic SA- 70; recurrent SA- 70) (Group I) and 140 age-matched controls (Group II) from Department of Obstetrics and Gynecology, Safdarjung Hospital, New Delhi, India. Polymerase chain reaction was performed for diagnosis of CT. The expression of iNOS/ eNOS/ IFN-γ/ TNF-α was assessed by real-time polymerase chain reaction (PCR).

Results: 15.7% SA were CT-positive (Group I); none in controls. Sporadic spontaneous aborters (SSA) (n = 8/70), recurrent spontaneous aborters (RSA) (n = 14/70) diagnosed as CT-positive (Group-I). Significant upregulation of iNOS/ eNOS was found in CT-positive SSA/RSA compared with CT-negative SSA/RSA and healthy controls. TNF-α and IFN-γ were expressed in CT-positive SSA/RSA compared with negative SSA/controls. iNOS showed a significant strong positive correlation with TNF-α and IFN-γ in CT-infected SA. eNOS showed a significant positive correlation with TNF-α and no correlation with IFN-γ in CT-infected SA. TNF-α was positively correlated with IFN-γ.

Conclusions: Significantly high expression of iNOS/ eNOS and proinflammatory cytokines affected pregnancy in CT-infected RSA, thereby implying that there occurs cytokine-induced expression of nitric oxide synthase (NOS).

Keywords:

• Chlamydia trachomatis
• cytokines
• endothelial nitric oxide synthase
• inducible nitric oxide synthase
• spontaneous aborters

Acknowledgment

P. P. thankfully acknowledges the award of Junior Research Fellowship (JRF) by Council of Scientific and Industrial Research (CSIR), New Delhi, India, and institutional Senior Research Fellowship (SRF). N. S. is grateful to University Grants Commission (UGC), New Delhi, India, for the award of JRF and also acknowledges institutional SRF.

Disclosure statement

No potential conflict of interest was reported by the authors.