RESUMO
The presymptomatic phase of Parkinson's disease (PD) is now recognized as a prodromal phase, with compensatory mechanism masking its progression and non-motor early manifestations, such as depression, cognitive disturbances and apathy. Those mechanisms were thought to be strictly dopamine-mediated until recent advances have shed light upon involvement of putative outside-basal ganglia, i.e. cortical, structures. We took advantage of our progressive 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated macaque model to monitor whole genome transcriptional changes in several brain areas. Our data reveals that transcriptomic activity changes take place from early stages, suggesting very early compensatory mechanisms or pathological activity outside the basal ganglia, including the PFC. Specific transcriptomic changes occurring in the PFC of fully parkinsonian MPTP-treated macaques have been identified. Interestingly, a large part of these transcriptomic changes were also observed in human post-mortem samples of patients with neurodegenerative diseases analysed by quantitative PCR. These results suggest that the PFC is able to detect the progression of dopamine denervation even at very early time points. There are therefore mechanisms, within the PFC, leading to compensatory alterations and/or participating to pathophysiology of prodromal PD manifestations.
Assuntos
Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Transtornos Parkinsonianos/genética , Transtornos Parkinsonianos/metabolismo , Córtex Pré-Frontal/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Globo Pálido/metabolismo , Humanos , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Putamen/metabolismo , RNA Mensageiro/metabolismo , Especificidade da Espécie , Tálamo/metabolismoRESUMO
BACKGROUND: Brain-expressed genes that were created in primate lineage represent obvious candidates to investigate molecular mechanisms that contributed to neural reorganization and emergence of new behavioural functions in Homo sapiens. PMCHL1 arose from retroposition of a pro-melanin-concentrating hormone (PMCH) antisense mRNA on the ancestral human chromosome 5p14 when platyrrhines and catarrhines diverged. Mutations before divergence of hylobatidae led to creation of new exons and finally PMCHL1 duplicated in an ancestor of hominids to generate PMCHL2 at the human chromosome 5q13. A complex pattern of spliced and unspliced PMCHL RNAs were found in human brain and testis. RESULTS: Several novel spliced PMCHL transcripts have been characterized in human testis and fetal brain, identifying an additional exon and novel splice sites. Sequencing of PMCHL genes in several non-human primates allowed to carry out phylogenetic analyses revealing that the initial retroposition event took place within an intron of the brain cadherin (CDH12) gene, soon after platyrrhine/catarrhine divergence, i.e. 30-35 Mya, and was concomitant with the insertion of an AluSg element. Sequence analysis of the spliced PMCHL transcripts identified only short ORFs of less than 300 bp, with low (VMCH-p8 and protein variants) or no evolutionary conservation. Western blot analyses of human and macaque tissues expressing PMCHL RNA failed to reveal any protein corresponding to VMCH-p8 and protein variants encoded by spliced transcripts. CONCLUSION: Our present results improve our knowledge of the gene structure and the evolutionary history of the primate-specific chimeric PMCHL genes. These genes produce multiple spliced transcripts, bearing short, non-conserved and apparently non-translated ORFs that may function as mRNA-like non-coding RNAs.
Assuntos
Hormônios Hipotalâmicos/genética , Precursores de Proteínas/genética , Splicing de RNA , RNA não Traduzido/genética , Adulto , Sequência de Aminoácidos , Animais , Encéfalo/metabolismo , Cromossomos Humanos Par 5/genética , Evolução Molecular , Éxons , Humanos , Íntrons , Macaca/genética , Masculino , Dados de Sequência Molecular , Filogenia , Primatas , RNA não Traduzido/metabolismo , Alinhamento de Sequência , Testículo/metabolismoRESUMO
Autologous fat grafting is a gold standard therapy for soft tissue defects, but is hampered by unpredictable postoperative outcomes. Fat graft enrichment with adipose-derived stromal cell (ASCs) was recently reported to enhance graft survival. Platelet-rich plasma (PRP) has also emerged as a biologic scaffold that promotes fat graft viability. Combined ASC/PRP fat grafting enrichment is thus a promising new regenerative medicine approach. The effects of PRP on ASC proliferation are well documented, but the impact of PRP on ASC differentiation has yet to be investigated in depth to further elucidate the PRP clinical effects. Here we analyzed the human ASC fate upon PRP treatment. PRP was found to sharply reduce the potential of ASCs to undergo differentiation into adipocytes. Interestingly, the PRP anti-adipogenic effect was accompanied by the generation of myofibroblast-like cells. Among the various factors released from PRP, TGFß pathway activators played a critical role in both the anti-adipogenic and pro-myofibroblastic PRP effects. Overall, these data suggest that PRP participates in maintaining a pool of ASCs and in the repair process by promoting ASC differentiation into myofibroblast-like cells. TGFß may provide an important target pathway to improve PRP clinical outcomes.