Premium
Mitochondrial Dysfunction Contributes to Germ Cell Apoptosis via the JNK/p53/ survivin Pathway
Author(s) -
Al-Maghrebi May,
Fadel Fatemah,
Al-Kandari Nora,
Khashab Farah,
Al-Saleh Farah
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.00029
Subject(s) - survivin , apoptosis , oxidative stress , tunel assay , western blot , biology , kinase , dna damage , microbiology and biotechnology , mitochondrion , reactive oxygen species , cytochrome c , superoxide dismutase , oxidative phosphorylation , mitochondrial dna , endocrinology , dna , biochemistry , gene
The aim is to show whether the c‐Jun N‐terminal kinases (JNK) signaling is a regulator of oxidative DNA damage, germ cell apoptosis (GCA) and mitochondrial dysfunction during testicular ischemia reperfusion injury (tIRI) using the JNK inhibitor SP600125. Male Sprague‐Dawley rats (n=36) were equally divided into 3 groups: sham, tIRI only and tIRI + SP600125 (15 mg/Kg, i.p.). Testicular ischemia was induced for 1 hour followed by 4 hours reperfusion prior to animal sacrifice. Spermatogenesis was evaluated by light microscopy using the Johnsen’s scoring system. Expression of oxidative stress and GCA genes and proteins were evaluated by real‐time PCR and colorimetric assays, respectively. Activation of the JNK/p53/survivin signaling pathway was detected by immunofluorescence (IF) staining. Indicators of mitochondrial dysfunction were examined by Western blot and colorimetric assays. In comparison to sham group, the tIRI testes showed a significant decrease in the antioxidant activity of superoxide dismutase, which was associated with increased lipid and protein oxidation products. Oxidative DNA damage was reflected by a significant increase in the number of single and double DNA strand breaks and increased concentration of 8‐OHdG DNA adducts. Spermatogenic damage was associated with the activation of caspases 9 and 3 and an elevated Bax to Bcl2 ratio. This was also accompanied by a significantly heightened IF expression of the phosphorylated forms of JNK and p53 paralleled with the down‐regulation of survivin. Mitochondrial dysfunction was reflected by NADH depletion, overexpression of uncoupling protein 2 and increased levels of cytochrome c protein. Such tIRI‐induced modulations were all attenuated by SP600125 treatment prior to reperfusion. In conclusion, mitochondrial dysfunction could contribute to GCA during tIRI under the control of the JNK/p53/survivin signaling pathway. Support or Funding Information This study was supported by Kuwait University Grants YM 15/17 (College of Graduate Studies ) and SRU02/13 (Research Administration).