The roles of p38 MAPK\u2009\u2192\u2009COX2 and NF-\u03baB\u2009\u2192\u2009COX2 signal pathways in age-related testosterone reduction

Yu Zhao,Dan Geng,Pin Lv,Yangyang Tian,Xuehui Liu,Wei Chen,Shiyang Chang,Xiujun Zhao,Yine Qu,Lixuan Wang,Li Li,Chunfang Zhao

doi:10.1038/s41598-019-46794-5

Yu Zhao, Dan Geng + Show 10 more

Open Access

https://doi.org/10.1038/s41598-019-46794-5

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Abstract

In our study, we explored changes in the redox status and inflammatory response in the testes of the SAMP8 model of varying ages (2, 4, 8, 10 months old) compared with control mice SAMR1 by the methods of immunohistochemical staining, Western blotting, RT-PCR and Luminex multi-analyte cytokine profiling. We found that as ROS and inflammation levels increased during aging, steroidogenic enzymes (StAR and P450scc) reduced and led to the decline of testosterone production eventually. The pathways of P38 MAPK → COX2 and NF-κB → COX2 were detected by using specific inhibitors of SB203580 and Bay 11-7082 in isolated Leydig cells. These results indicated that activation of both p38 MAPK → COX2 and NF-κB → COX2 signaling pathways are functionally linked to the oxidative stress response and chronic inflammation during aging, and mediate their inhibitory effects on testosterone production.

Highlights

Material and MethodsThe viability of Leydig cell preparations was detected by incubating with 0.4% Trypan blue for 5 minutes
We found that as ROS and inflammation levels increased during aging, steroidogenic enzymes (StAR and P450scc) reduced and led to the decline of testosterone production eventually
The pathways of P38 mitogen-activated protein kinase (MAPK) → COX2 and NF-κB → COX2 were detected by using specific inhibitors of SB203580 and Bay 11-7082 in isolated Leydig cells. These results indicated that activation of both p38 MAPK → COX2 and NF-κB → COX2 signaling pathways are functionally linked to the oxidative stress response and chronic inflammation during aging, and mediate their inhibitory effects on testosterone production

Summary

Material and Methods

The viability of Leydig cell preparations was detected by incubating with 0.4% Trypan blue for 5 minutes. Leydig cells from young (4 month age) and old (8–10 month age) mice were incubated in the absence (basal) or in the presence of the maximum dose of LH (100 ng/ml) for 2 h. To assess the concentration and the incubation times of Bay as previously described[17], old Leydig cells were treated with 0–10 μM of Bay for 12 h and incubated with 5 μM Bay for the different time periods (from 0 to 24 h). The medium were collected, frozen and cryopreserved until testosterone levels were analyzed as described above. XMAP technology (Austin, TX, USA) was used to measure cytokine levels as my last paper described[3]. Data were analyzed using two-way ANOVA with complete random design, and multiple pair-wise comparison was performed using Student-Newman-Keuls post hoc tests

Results

Discussion

Summary and Conclusions