RESUMO
Spermatozoa harbour a complex and environment-sensitive pool of small non-coding RNAs (sncRNAs)1, which influences offspring development and adult phenotypes1-7. Whether spermatozoa in the epididymis are directly susceptible to environmental cues is not fully understood8. Here we used two distinct paradigms of preconception acute high-fat diet to dissect epididymal versus testicular contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNAs (mt-tRNAs) and their fragments (mt-tsRNAs) as sperm-borne factors. In humans, mt-tsRNAs in spermatozoa correlate with body mass index, and paternal overweight at conception doubles offspring obesity risk and compromises metabolic health. Sperm sncRNA sequencing of mice mutant for genes involved in mitochondrial function, and metabolic phenotyping of their wild-type offspring, suggest that the upregulation of mt-tsRNAs is downstream of mitochondrial dysfunction. Single-embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tRNAs at fertilization and suggested their involvement in the control of early-embryo transcription. Our study supports the importance of paternal health at conception for offspring metabolism, shows that mt-tRNAs are diet-induced and sperm-borne and demonstrates, in a physiological setting, father-to-offspring transfer of sperm mitochondrial RNAs at fertilization.
Assuntos
Dieta Hiperlipídica , Epigênese Genética , Mitocôndrias , RNA Mitocondrial , Espermatozoides , Animais , Feminino , Humanos , Masculino , Camundongos , Índice de Massa Corporal , Dieta Hiperlipídica/efeitos adversos , Embrião de Mamíferos/citologia , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Epididimo/citologia , Epigênese Genética/genética , Fertilização/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Obesidade/genética , Obesidade/metabolismo , Obesidade/etiologia , Oócitos/metabolismo , Sobrepeso/genética , Sobrepeso/metabolismo , Herança Paterna/genética , RNA Mitocondrial/genética , RNA Mitocondrial/metabolismo , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Espermatozoides/metabolismo , Testículo/citologia , Transcrição GênicaRESUMO
OBJECTIVE: Although debated, metabolic health characterizes 10-25% of obese individuals and reduces risk of developing life-threatening co-morbidities. Adipose tissue is a recognized endocrine organ important for the maintenance of whole-body metabolic health. Adipocyte transcriptional signatures of healthy and unhealthy obesity are largely unknown. METHODS: Here, we used a small cohort of highly characterized obese individuals discordant for metabolic health, characterized their adipocytes transcriptional signatures, and cross-referenced them to mouse phenotypic and human GWAs databases. RESULTS AND CONCLUSIONS: Our study showed that glucose intolerance and insulin resistance co-operate to remodel adipocyte transcriptome. We also identified the Nuclear Export Mediator Factor (NEMF) and the Ectoderm-Neural Cortex 1 (ENC1) as novel potential targets in the management of metabolic health in human obesity.
Assuntos
Adipócitos/metabolismo , Intolerância à Glucose , Resistência à Insulina , Obesidade/metabolismo , Transcriptoma , Adulto , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Células Cultivadas , Feminino , Humanos , Masculino , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Pessoa de Meia-Idade , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático/genética , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Obesidade/genéticaRESUMO
Homeodomain-interacting protein kinase 2 (HIPK2) is a multitalented coregulator of an increasing number of transcription factors and cofactors involved in cell death and proliferation in several organs and systems. As Hipk2(-/-) mice show behavioral abnormalities consistent with cerebellar dysfunction, we investigated whether Hipk2 is involved in these neurological symptoms. To this aim, we characterized the postnatal developmental expression profile of Hipk2 in the brain cortex, hippocampus, striatum, and cerebellum of mice by real-time PCR, western blot analysis, and immunohistochemistry. Notably, we found that whereas in the brain cortex, hippocampus, and striatum, HIPK2 expression progressively decreased with age, that is, from postnatal day 1 to adulthood, it increased in the cerebellum. Interestingly, mice lacking Hipk2 displayed atrophic lobules and a visibly smaller cerebellum than did wild-type mice. More important, the cerebellum of Hipk2(-/-) mice showed a strong reduction in cerebellar Purkinje neurons during adulthood. Such reduction is due to the activation of an apoptotic process associated with a compromised proteasomal function followed by an unpredicted accumulation of ubiquitinated proteins. In particular, Purkinje cell dysfunction was characterized by a strong accumulation of ubiquitinated ß-catenin. Moreover, our behavioral tests showed that Hipk2(-/-) mice displayed muscle and balance impairment, indicative of Hipk2 involvement in cerebellar function. Taken together, these results indicate that Hipk2 exerts a relevant role in the survival of cerebellar Purkinje cells and that Hipk2 genetic ablation generates cerebellar dysfunction compatible with an ataxic-like phenotype.