Project description:In order to uncover mechanisms of hBMSC senescence, we performed high-throughput RNA-seq using young and senile human bone MSC (hBMSC).
Project description:Mesenchymal stromal cells (MSC) are ideal candidates for cell therapies, due to their immune-regulatory and regenerative properties. We have previously reported that lung-derived MSC are tissue-resident cells with lung-specific properties compared to bone marrow-derived MSC. Assessing relevant molecular differences between lung-MSC and bone marrow-MSC is important, given that such differences may impact their behavior and potential therapeutic use. Here, we present an in-depth mass spectrometry (MS) based strategy to investigate the proteomes of lung-MSC and bone marrow-MSC. The MS-strategy relies on label free quantitative data-independent acquisition (DIA) analysis and targeted data analysis using a MSC specific spectral library. We identified several significantly differentially expressed proteins between lung-MSC and bone marrow-MSC within the cell layer (352 proteins) and in the conditioned medium (49 proteins). Bioinformatics analysis revealed differences in regulation of cell proliferation, which was functionally confirmed by decreasing proliferation rate through Cytochrome P450 stimulation. Our study reveals important tissue-specific differences within proteome and matrisome profiles between lung- and bone marrow-derived MSC that may influence their behavior and affect the clinical outcome when used for cell-therapy.
Project description:Age-related cell loss underpins many senescence-associated diseases. Senile cataract is a primary blindness-causing age-related ocular disease. Apoptosis of lens epithelial cells (LECs) is the common cellular basis of senile cataract resulted from prolonged exposure to oxidative stress, the mechanism of which remains elusive. Here we reported the concomitance of increased autophagy and apoptosis in the same LEC from senile cataract patients. Oxidative stress triggered autophagy preceded apoptosis, while blocking autophagy by ablation of Atg7 or Atg3 gene remarkably suppressed apoptosis in HLE-B3 cell line. We identified autophagy adaptor SQSTM1/p62 as the critical scaffold protein to sustain a pro-survival signaling PKCι-NF-κB cascades, which antagonized the pro-apoptotic signaling in LECs. Importantly, prolonged autophagy in human senescent LECs responding to oxidative stress induced extensive degradation of p62 protein and therefore facilitated apoptosis. Moreover, pharmacological inhibitor of autophagy, 3-MA, significantly rescued apoptosis of human senescent LECs challenged by oxidative stress. Collectively, our data demonstrated that hyperactivation of autophagy aggravates age-related apoptotic cell death via inhibiting the p62-PKCι-NF-κB pro-survival axis in human senescent LECs. This work expands the understanding of the etiology of senile cataract and provides insight for mechanisms of age-related cell death in senescence-associated diseases.
Project description:miRNA profiles of the Young-MSC-MVs and Old-MSC-MVs were analyzed with a quantitative PCR (qPCR)-based array of the whole rat genome. Further analysis revealed the expression of miR-344a, miR-133b-3p, miR-294, miR-423-3p, and miR-872-3p was significantly downregulated in Old-MSC-MVs than in Young-MSC-MVs (p<0.05).
Project description:Skin aging is a process of structural and compositional remolding that can be manifested as wrinkling and sagging. Remarkably, the dermis plays a dominant role in the process of skin aging. Recent studies suggest that microRNAs (miRNAs) may play a role in the regulation of gene expression in organism aging. However, studies about age-related miRNAs in human skin remain limited. In order to obtain an overall view of miRNAs expression in human aged dermis, we have investigated the alteration of microRNAs during aging by examining biopsies of human dermis from 12 young and aged donors, and demonstrated that numerous microRNAs showed significant alteration in dermis tissue. Normal human dermal tissue from 12 consenting individuals. Old group vs young group. Old group: with the age over 60 years old; young group: with the age below 10 years old; each group was constituted of 6 individuals.
Project description:The deposition of amyloid senile plaques (SPs) play a central role in Alzheimer’s disease (AD), but the mechanisms by which SPs induce neural toxicity are disputed. Genetically engineered mouse models emphasising SPs have had limited success in reproducing the neuropathology of AD, and have also failed to be good indicators of successful amyloid-targeting therapies. Moreover, elderly people with a heavy plaque burden can show normal cognition. Therefore, it is fundamentally important to fully characterize and distinguish the pathological changes elicited by SPs in human and mouse brains. Using laser capture microdissection (LCM) combined with high-throughput mass spectrometry, we quantified ~5000 proteins with high confidence in SPs and non-plaque regions from AD and non-AD human postmortem brain. We found proteomic alteration in SPs is more evident than in non-plaque regions, and identified more than 30 human that are significantly enriched in SPs. We found that AD SPs elicited much more extensive proteomic alterations compared to non-AD SPs. Together, our findings represent the most systematic analysis of sub-proteome of senile plaques and provide a framework for future studies on plaque pathology and AD progression.