Ubiquitin protein E3 ligase ASB9 suppresses proliferation and promotes apoptosis in human spermatogonial stem cell line by inducing HIF1AN degradation

BACKGROUND: Spermatogonial stem cells (SSCs) are critical for sustaining spermatogenesis. Even though several regulators of SSC have been identified in rodents, the regulatory mechanism of SSC in humans has yet to be discovered. METHODS: To explore the regulatory mechanisms of human SSCs, we analyzed publicly available human testicular single-cell sequencing data and found that Ankyrin repeat and SOCS box protein 9 (ASB9) is highly expressed in SSCs. We examined the expression localization of ASB9 using immunohistochemistry and overexpressed ASB9 in human SSC lines to explore its role in SSC proliferation and apoptosis. Meanwhile, we used immunoprecipitation to find the target protein of ASB9 and verified its functions. In addition, we examined the changes in the distribution of ASB9 in non-obstructive azoospermia (NOA) patients using Western blot and immunofluorescence. RESULTS: The results of uniform manifold approximation and projection (UMAP) clustering and pseudotime analysis showed that ASB9 was highly expressed in SSCs, and its expression gradually increased during development. The immunohistochemical and dual-color immunofluorescence results displayed that ASB9 was mainly expressed in nonproliferating SSCs. Overexpression of ASB9 in the SSC line revealed significant inhibition of cell proliferation and increased apoptosis. We predicted the target proteins of ASB9 and verified that hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), but not creatine kinase B-type (CKB), has a direct interaction with ASB9 in human SSC line using protein immunoprecipitation experiments. Subsequently, we re-expressed HIF1AN in ASB9 overexpressing cells and found that HIF1AN reversed the proliferative and apoptotic changes induced by ASB9 overexpression. In addition, we found that ABS9 was significantly downregulated in some NOA patients, implying a correlation between ASB9 dysregulation and impaired spermatogenesis. CONCLUSION: ASB9 is predominantly expressed in human SSCs, it affects the proliferation and apoptotic process of the SSC line through HIF1AN, and its abnormal expression may be associated with NOA.

Pathways of IFN-alpha Activation in Patients with Cervical Intraepithelial Neoplasia (CIN) / Vias de ativação de IFN-alfa em pacientes com Neoplasia Intraepitelial Cervical (NIC)

Abstract Objective The aim of the present study was to compare the local and systemic expression of the factors linked to the interferon alpha (IFN-α) activation pathway in different degrees of cervical intraepithelial neoplasia (CIN) and cervical cancer. Methods A total of 128 patients with CIN I, CIN II, CIN III and cervical cancer was evaluated. The real-time polymerase chain reaction (RT-PCR) technique was used to evaluate the gene expression of IFNR1, IFNR2, IFN-α, oligoadenylate synthase (2'5′OAS), cytokine signal suppressor 1 (SOCS) 1, SOCS3, signal transducer and transcription activator 1 (STAT1), and IRF9 from 128 biopsies. A total of 46 out of 128 samples were evaluated by flow cytometry for IFNAR1, IFNAR2, STAT1, IRF7 and IFN-α in peripheral blood cells. Results Patients with CIN II and III (63 samples) had a low local expression of IFNR1, but not IFNR2. Patients with some degree of injury showed high expression of SOCS1 and SOCS3. Systemically, patients with CIN II and III (20 samples) had a significant increase in IFNR1, IFNR2, STAT1, IRF7, and IFN-α in helper, cytotoxic T lymphocytes, and in monocytes. Conclusion Patients with high-grade lesions have increased systemic expression of IFN-α and its activation pathways in helper and cytotoxic T lymphocytes, as well as in monocytes due to an exacerbation of the immune response in these patients. This phenomenon is not accompanied by resolution of the lesion due to a defect in the IFN-α activation pathway that revealed by low local IFNAR1 expression and high local expression of SOCS1 and SOCS3.

Resumo Objetivo O objetivo do presente estudo foi comparar a expressão local e sistêmica dos fatores ligados à via de ativação do interferon alfa (IFN-α) em diferentes graus de neoplasia intraepitelial cervical (NIC) e câncer cervical (CA) Métodos Foram avaliados 128 pacientes com NIC I, NIC II, NIC III e CA. A técnica de reação de cadeia de polimerase em tempo real (RT-PCR, na sigla em inglês) foi realizada para avaliar a expressão gênica do receptor de interferon (IFNR) 1, IFNR2, IFN-α, 2′-5′- oligoadenilato sintetase (2′5′OAS), supressor de sinalização de citocina (SOCS)1, SOCS3, transdutor de sinal e ativador de transcrição 1 (STAT1) e fator regulador de interferon 9 (IRF9) das 128 biópsias. Das 128 amostras, 46 foram avaliadas por citometria de fluxo para IFNAR1, IFNAR2, STAT1, IRF7 e IFN-α em células de sangue periférico. Resultados Pacientes com NIC II e III (63 amostras) tiveram baixa expressão local de IFNR1 mas não de IFNR2. Pacientes com algum grau de lesão apresentaram alta expressão de SOCS1 e SOCS3. Sistemicamente, os pacientes com NIC II e III (20 amostras) tiveram um aumento significativo de IFNR1, IFNR2, STAT1, IRF7 e IFN-α em linfócitos T auxiliares, citotóxicos e monócitos. Conclusão Pacientes com lesões de alto grau apresentam expressão sistêmica aumentada de IFN-α e suas vias de ativação em linfócitos T auxiliares e citotóxicos, bem como em monócitos, devido à exacerbação da resposta imune nesses pacientes. Este fenômeno não é acompanhado pela resolução da lesão devido a um defeito na via de ativação do IFN-α que é revelado pela baixa expressão local de IFNR1 e alta expressão local de SOCS1 e SOCS3.