RESUMO
Male reproductive toxicity of fluoride is of great concern worldwide, yet the underlying mechanism is unclear. Pyroptosis is a novel mode of inflammatory cell death, and riboflavin with anti-inflammatory properties has the potential to protect against fluoride damage. However, it is unknown whether pyroptosis is involved in fluoride-induced testicular injury and riboflavin intervention. Here, we first found that riboflavin could alleviate fluoride-caused lower sperm quality and damaged testicular morphology by reducing pyroptosis based on a model of ICR mice treated with NaF (100 mg/L) and/or riboflavin supplementation (40 mg/L) via drinking water for 13 weeks. And then, together with the results of in vitro Leydig cell modelsm it was confirmed that the pyroptosis occurs predominantly through classical NLRP3/Caspase-1/GSDMD pathway. Furthermore, our results reveal that interleukin-17A mediates the process of pyroptosis in testes induced by fluoride and riboflavin attenuation according to the results of our established models of riboflavin- and/or fluoride-treated IL-17A knockout mice. The results not only declare a new mechanism by which fluoride induces testicular injury via interleukin 17A-mediated classical pyroptosis but also provide evidence for the potential clinical application of riboflavin as an effective therapy for fluoride toxicity.
Assuntos
Fluoretos , Piroptose , Animais , Camundongos , Masculino , Fluoretos/farmacologia , Interleucina-17 , Camundongos Endogâmicos ICR , Sêmen/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismoRESUMO
The impairment of the immune system by fluoride is a public health concern worldwide, yet the underlying mechanism is unclear. Both riboflavin and IL-17A are closely related to immune function and regulate the testicular toxicity of fluoride. However, whether riboflavin or IL-17A is involved in fluoride-induced immunotoxicity is unknown. Here, we first established a male ICR mouse model by treating mice with sodium fluoride (NaF) (100 mg/L) via the drinking water for 91 days. The results showed that fluoride increased the expression of the proinflammatory factors IL-1ß and IL-17A, which led to splenic inflammation and morphological injury. Moreover, the expression levels of the riboflavin transporters SLC52A2 and SLC52A3; the transformation-related enzymes RFK and FLAD1; and the key mitochondrial functional determinants SDH, COX, and ATP in the spleen were measured via real-time PCR, Western blotting, and ELISA. The results revealed that fluoride disrupted riboflavin transport, transformation, metabolism, and mitochondrial function. Furthermore, wild-type (WT) and IL-17A knockout (IL-17A-/-) C57BL/6 J male mice of the same age were treated with NaF (24 mg/kg·bw, equivalent to 100 mg/L) and/or riboflavin sodium phosphate (5 mg/kg·bw) via gavage for 91 days. Similar parameters were evaluated as above. The results confirmed that fluoride increased riboflavin metabolism through RFK but not through FLAD1. Fluoride also affected mitochondrial function and activated neutrophils (marked with Ly6g) and macrophages (marked with CD68) in the spleen. Interestingly, IL-17A partly mediated fluoride-induced riboflavin metabolism disorder and immunotoxicity in the spleen. This work not only reveals a novel toxic mechanism for fluoride but also provides new clues for exploring the physiological function of riboflavin and for diagnosing and treating the toxic effects of fluoride in the environment.
Assuntos
Interleucina-17 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Riboflavina , Fluoreto de Sódio , Baço , Animais , Masculino , Interleucina-17/metabolismo , Baço/efeitos dos fármacos , Baço/metabolismo , Fluoreto de Sódio/toxicidade , Camundongos Knockout , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Transporte BiológicoRESUMO
INTRODUCTION: Fluorosis is a global public health disease affecting more than 50 countries and 500 million people. Excessive fluoride damages the liver and intestines, yet the mechanisms and therapeutic approaches remain unclear. OBJECTIVES: To explore the mechanisms by which fluoride-induced intestinal-hepatic damage and vitamin B2 alleviation. METHODS: Fluoride and/or vitamin B2-treated IL-17A knockout and wild-type mouse models were established, the morphological and functional changes of liver and gut, total bile acid biosynthesis, metabolism, transport, and regulation of FXR-FGF15 signaling pathways were evaluated, the ileal microbiome was further analyzed by 16S rDNA sequence. Finally, Bifidobacterium supplementation mouse model was designed and re-examined the above indicators. RESULTS: The results demonstrated that fluoride induced hepatointestinal injury and enterohepatic circulation disorder by altering the synthesis, transporters, and FXR-FGF15 pathway regulation of total bile acid. Importantly, the ileum was found to be the most sensitive and fluoride changed ileal microbiome particularly by reducing abundance of Bifidobacterium. While vitamin B2 supplementation attenuated fluoride-induced enterohepatic circulation dysfunction through IL-17A and ileal microbiome, Bifidobacterium supplementation also reversed fluoride-induced hepatointestinal injury. CONCLUSION: Fluoride induces morphological and functional impairment of liver and gut tissues, as well as enterohepatic circulation disorder by altering total bile acid (TBA) synthesis, transporters, and FXR-FGF15 signaling regulation. Vitamin B2 attenuated fluoride-induced enterohepatic circulation disorder through IL-17A knockout and ileal microbiome regulation. The ileum was found to be the most sensitive to fluoride, leading to changes in ileal microbiome, particularly the reduction of Bifidobacterium. Furthermore, Bifidobacterium supplementation reversed fluoride-induced hepatointestinal injury. This study not only elucidates a novel mechanism by which fluoride causes hepatointestinal toxicity, but also provides a new physiological function of vitamin B2, which will be useful in the therapy of fluorosis and other hepatoenterological diseases.
RESUMO
Arsenic (As) poisoning and its potential reproductive functional lesions are a global environmental concern. Recent studies shown that spermiogenesis tends to be a major target process in arsenic-induced male infertility, however, the underlying mechanisms are not fully illuminated. In the present study, 32 fertility related indices including sperm motility, dynamic acrosome formation and sperm flagellum during spermiogenesis in testes were evaluated in adult male mice treated with 0, 0.2, 2, and 20 ppm As2O3 via drinking water for 180 consecutive days. The results showed that out of 32 indices, 11, 25, and 29 indicators were changed statistically by 0.2-, 2-, and 20- ppm As2O3 treatment compared to the controls (0 ppm As2O3), respectively, which reveals a significant dose-dependent relationship. For details, sperm motilities were significantly decreased by 18.85%, 32.47% and 29.53% in three As2O3 treatment groups compared to the control group. Meanwhile, the ultra-structures of acrosome formation and sperm flagellum in testes have been altered by chronic arsenic exposure. Furthermore, arsenic decreased the mRNA expressions of 11 out of 13 genes associated with acrosome biosynthesis and 11 out of 12 genes related to flagellum formation in testes, particularly, down-regulated DPY19L2, AKAP3, AKAP4, CFAP44 and SPAG16 were further confirmed at the protein levels by western blotting. Taken together, chronic arsenic exposure declines male fertility by disorganizing dynamic acrosome and flagellum formation in testes. Especially, DPY19L2, AKAP3, AKAP4, CFAP44, and SPAG16 maybe the potential targets in this process. These results may offer not only a new insight to the mechanism of arsenic-induced male reproductive toxicity, but also provide a clue for the diagnosis and therapy of arseniasis.
Assuntos
Acrossomo , Proteínas de Ancoragem à Quinase A , Animais , Arsênio , Flagelos , Masculino , Proteínas de Membrana , Camundongos , Motilidade dos Espermatozoides , Espermatogênese , EspermatozoidesRESUMO
Basal-like breast cancer (BLBC) is associated with a poor clinical outcome as a result of the few treatment options and poor therapeutic response. Here, we report that elevated expression of urine diphosphate-galactose ceramide galactosyltransferase (UGT8) specifically occurs in BLBC and predicts poor prognosis in breast cancer patients. UGT8 expression is transcriptionally up-regulated by Sox10, triggering the sulfatide biosynthetic pathway; increased sulfatide activates integrin αVß5-mediated signaling that contributes to BLBC progression. UGT8 expression promotes, whereas UGT8 knockdown suppresses tumorigenicity and metastasis. Importantly, we identify that zoledronic acid (ZA), a marketed drug for treating osteoporosis and bone metastasis, is a direct inhibitor of UGT8, which blocks the sulfatide biosynthetic pathway. Significantly, a clinically achievable dosage of ZA exhibits apparent inhibitory effect on migration, invasion, and lung metastasis of BLBC cells. Together, our study suggests that UGT8 is a potential prognostic indicator and druggable target of BLBC and that pharmacologic inhibition of UGT8 by ZA offers a promising opportunity for treating this challenging disease.