Proteome profiling of different rat brain regions reveals the modulatory effect of prolonged maternal separation on proteins involved in cell death-related processes

BACKGROUND: Early-life stress in the form of maternal separation can be associated with alterations in offspring neurodevelopment and brain functioning. Here, we aimed to investigate the potential impact of prolonged maternal separation on proteomic profiling of prefrontal cortex, hippocampus and cerebellum of juvenile and young adult rats. A special attention was devoted to proteins involved in the process of cell death and redox state maintenance. METHODS: Long-Evans pups were separated from their mothers for 3 h daily over the first 3 weeks of life (during days 2-21 of age). Brain tissue samples collected from juvenile (22-day-old) and young adult (90-day-old) rats were used for label-free quantitative (LFQ) proteomic analysis. In parallel, selected oxidative stress markers and apoptosis-related proteins were assessed biochemically and by Western blot, respectively. RESULTS: In total, 5526 proteins were detected in our proteomic analysis of rat brain tissue. Approximately one tenth of them (586 proteins) represented those involved in cell death processes or regulation of oxidative stress balance. Prolonged maternal separation caused changes in less than half of these proteins (271). The observed alterations in protein expression levels were age-, sex- and brain region-dependent. Interestingly, the proteins detected by mass spectrometry that are known to be involved in the maintenance of redox state were not markedly altered. Accordingly, we did not observe any significant differences between selected oxidative stress markers, such as the levels of hydrogen peroxide, reduced glutathione, protein carbonylation and lipid peroxidation in brain samples from rats that underwent maternal separation and from the corresponding controls. On the other hand, a number of changes were found in cell death-associated proteins, mainly in those involved in the apoptotic and autophagic pathways. However, there were no detectable alterations in the levels of cleaved products of caspases or Bcl-2 family members. Taken together, these data indicate that the apoptotic and autophagic cell death pathways were not activated by maternal separation either in adolescent or young adult rats. CONCLUSIONS: Prolonged maternal separation can distinctly modulate expression profiles of proteins associated with cell death pathways in prefrontal cortex, hippocampus and cerebellum of juvenile rats and the consequences of early-life stress may last into adulthood and likely participate in variations in stress reactivity.

Protein profiling of SH-SY5Y neuroblastoma cells: The effect of rhein

Bone marrow mesenchymal stem cells (BMSCs) play an important role in the process of bone repair. The present studyinvestigated the effect of 5-azacytidine (AZA) and trichostatin A (TSA) on BMSC behaviors in vitro. The role of WNTfamily member 5A (WNT5A)/WNT family member 5A (WNT7A)/b-catenin signaling was also investigated. BMSCs wereisolated from a steroid-induced avascular necrosis of the femoral head (SANFH) rabbit model. The third-generation ofBMSCs was used after identification. The results revealed obvious degeneration and necrosis in the SANFH rabbit model.AZA, TSA and TSA ? AZA increased BMSC proliferation in a time-dependent fashion. AZA, TSA and TSA ? AZAinduced the cell cycle release from the G0/G1 phase and inhibited apoptosis in BMSCs. AZA, TSA and TSA ? AZAtreatment significantly decreased caspase-3 and caspase-9 activities. The treatment obviously increased the activity andrelative mRNA expression of alkaline phosphatase. The treatment also significantly up-regulated the proteins associatedwith osteogenic differentiation, including osteocalcin and runt-related transcription factor 2 (RUNX2), and Wnt/b-cateninsignal transduction pathway-related proteins b-catenin, WNT5A and WNT7A. The relative levels of Dickkopf-relatedprotein 1 (an inhibitor of the canonical Wnt pathway) decreased remarkably. Notably, TSA ? AZA treatment exhibited astronger adjustment ability than either single treatment. Collectively, the present studies suggest that AZA, TSA and TSA ?AZA promote cell proliferation and osteogenic differentiation in BMSCs, and these effects are potentially achieved via upregulation of WNT5A/WNT7A/b-catenin signaling.