Dolutegravir impairs mitochondrial ATP production and increases syncytialization in human trophoblast cells

Dolutegravir (DTG) together with other Integrase strand transfer inhibitor regimens has improved the effectiveness of HIV treatment, however, accumulating evidence suggests that DTG is associated with weight gain and other metabolic effects, such as hyperglycemia and changes in folate metabolism, in both nonpregnant and pregnant adults with HIV. To date, the impact of these metabolic effects on pregnancy outcomes is unknown. The placenta maintains pregnancy, supports fetal growth and development, and predisposes adulthood diseases, and placental development and functions rely on mitochondrial functions and hemostasis. In this study, we hypothesized that DTG interferes with mitochondrial functions and homeostasis in human trophoblast cells. To test this hypothesis, human trophoblast cell line BeWo was treated with DTG at different doses (0.004-40 µg/ml), followed by cytotoxicity assay by propidium iodide (PI) staining. The mitochondrial membrane potential was measured by Tetramethylrhodamine methyl ester (TMRM) staining. The mitochondrial mass was measured by MitoTracker green staining. The Mitochondrial ATP production was measured by Seahorse cell mito stress test. To investigate the effect of DTG on syncytiotrophoblast formation, BeWo cells were treated with forskolin (20µM) for 48 hours, and the expression of syncytialization related genes (CGB, ERVW1, ERVFRD-1, CDH1, TJP11, HSD11B2) was analyzed by q-PCR and normalized to that of ribosomal 18S. All numerical parameters between the DTG treatment and control groups were analyzed by ANOVA (n=3 or 5). Main findings include: 1) The Cmax dose of DTG, 4 µg/ml, increased the cell death by 1.54-fold ( p <0.001), compared to controls; 2) At the dose of 4 µg/ml, DTG did not alter the mitochondrial membrane potential; 3) DTG did not alter the mitochondrial mass; 4) DTG reduced basal and maximum mitochondrial ATP production by 1.42- and 1.53-fold, respectively ( p <0.01), concomitant with reduced spare respiratory capacity and non-mito respiration; 5) DTG may stimulate trophoblast cell syncytialization in presence of forskolin, increasing expression of ERVFRD-1 (Syncytin-2) and HSD11B2 by 1.85-and 2.02-fold, respectively ( p <0.01), compared to forskolin alone. These results indicate that DTG may cause metabolic effects by reducing mitochondrial ATP production in trophoblast cells and by enhancing trophoblast syncytialization, and therefore, these two mechanisms can serve as intervention targets to prevent side-effects of HIV therapy. Supported by DC CFAR Pilot Award and NIH research grant R16HD116702. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.