Hexafluoropropylene oxide (HFPO) homologues (HFPOs), specifically HFPO-dimeric acid (DA), HFPO-trimeric acid (TA) and HFPO-tetrameric acid (TeA), have emerged as industrial replacements for phased-out perfluorooctanoic acid (PFOA), garnering considerable attention due to their environmental ubiquity and bioaccumulation potential. Nevertheless, the reproductive toxicity of HFPOs remains incompletely characterized, particularly regarding their endocrine-disrupting effect and the underlying mechanisms involving Leydig cell dysfunction. In this study, we investigated the cytotoxic influences of HFPOs on TM3 Leydig cells, focusing on mitochondrial function and dynamics, oxidative stress, and apoptosis. Our findings demonstrated that exposure to HFPOs significantly compromised mitochondrial function and fusion-fission dynamics by disrupting the SIRT1/PGC1α signaling pathway. The mitochondrial dysfunction further triggered excessive ROS production and apoptosis, ultimately impairing TM3 Leydig cell viability and testosterone secretion. However, supplementation with the SIRT1 agonist SRT1720 relieved the inhibitory effect of HFPOs on SIRT1/PGC1α signaling pathway and reversed the expression of apoptosis-associated proteins (BAX/BCL2), oxidative stress-associated proteins (SOD1/SOD2), as well as proteins associated with mitochondrial fusion (MFN2/OPA1) and fission (DRP1/FIS1). These results elucidated the involvement of the SIRT1/PGC1α pathway in mediating the cytotoxicity of HFPOs. Notably, the activation of SIRT1 mitigated HFPO-induced toxicity in the TM3 cells, uncovering its potential in safeguarding testicular cells from the damage caused by HFPOs exposure.
Xiaoyan He,Jiwei Liu,Tao Song,Yiying Sun,Xiaoyan Lu,Nuannuan Li,Kaoxiang Sun
A satisfactory drug release profile for gonadotropin-releasing hormone (GnRH) agonist drugs is high initial release followed by small amount of drug release per day. In the present study, three water-soluble additives (NaCl, CaCl2 and glucose) were selected to improve the drug release profile of a model GnRH agonist drug-triptorelin from PLGA microspheres. The pore manufacturing efficiency of the three additives was similar. The effects of three additives on drug release were evaluated. Under the optimal initial porosity, the initial release amount of microspheres containing different additives was comparable, this ensured a good inhibitory effect on testosterone secretion in the early stage. For NaCl or CaCl2 containing microspheres, the drug remaining in the microsphere depleted rapidly after the initial release. The testosterone concentration gradually returned to an uncontrolled level. However, for glucose containing microspheres, it was found that the addition of glucose could not only increase the initial release of the drug but also assist in the subsequent controlled drug release. A good and long-time inhibitory effect on testosterone secretion was observed in this formulation. The underlying cause why the incorporation of glucose delayed the subsequent drug release was investigated. SEM results showed that considerable pores in glucose containing microspheres were healed during the microspheres incubation. After thermal analysis, an obvious glass transition temperature (Tg) depression was observed in this formulation. As Tg decreased, polymer chains are able to rearrange at lower temperatures. This, morphologic change was reflected in the gradual closure of the pores, and is the likely reason that drug release slowed down after the initial release.HIGHLIGHTSThe addition of glucose could not only increase the burst release of the drug but also delay the subsequent drug release.High initial burst and a sustained drug release helped obtain a good inhibitory effect on testosterone secretion.As Tg decreased, polymer chain was prone to rearrange. Morphologic change was reflected in the gradual closure of the pores. This was the reason that drug release slowed down after the initial burst.