Can probability of genetic mutation be an indicator of clinical relevance?

AbstractNPM1 gene mutation evaluated on a population basis is a valuable and realistic tool to reflect the pathophysiological relevance of cancer. In a comparison of the NPM1 cDNA of human bladder cancer with its consensus sequence, we have found that a higher NPM1 sequence identity in a population is consistent with poor tumor differentiation, advanced tumor stage, and likelihood of recurrence. These data imply that “probability” of NPM1 mutation is an indicator of status of malignancy

Dephosphorylation of Nucleophosmin by PP1β Facilitates pRB Binding and Consequent E2F1-dependent DNA Repair

We report a new pathway through which PP1β signals to nucleophosmin (NPM) in response to DNA damage. UV induces dephosphorylation of NPM at multiple sites, leading to enhancement of complex formation between NPM and retinoblastoma tumor suppressor protein and the subsequent upregulation of E2F1. Consequently, such signaling pathway potentiates the cellular DNA repair capacity

The cytoprotective role of autophagy in puromycin aminonucleoside treated human podocytes

Autophagy is a ubiquitous catabolic process involving degradation of damaged organelles and protein aggregates. It shows cytoprotective effects in many cell types and helps to maintain cell homeostasis. In many glomerular diseases, podocyte damage leads to the disruption of the renal filtration barrier and subsequent proteinuria. Puromycin aminonucleoside (PAN) which induces podocyte apoptosis in vitro and in vivo is widely used for studying the pathophysiology of glomerular diseases. It has been shown that PAN induces autophagy in podocytes. However, the relationship between autophagy and apoptosis in PAN treated human podocytes is not known and the role of PAN-induced autophagy in podocyte survival remains unclear. Here we demonstrate that PAN induced autophagy in human podocytes prior to apoptosis which was featured with the activation of mTOR complex 1 (mTORC1). When the PAN-induced autophagy was inhibited by 3-methyladenine (3-MA) or chloroquine (CQ), podocyte apoptosis increased significantly along with the elevation of active caspase-3. Under such circumstance, the podocyte cytoskeleton was also disrupted. Collectively, our results suggested that the induced autophagy may be an early adaptive cytoprotective mechanism for podocyte survival after PAN treatment.Department of Health Technology and Informatic

Trehalose-induced podocyte autophagy was independent of ROS.

<p>Trehalose-induced autophagy was not associated with energy restriction and ROS. (<b>A</b>) Trehalose-treated podocytes (50 mM) were harvested for p-AMPK measurement at the time points of 0, 12, 24, 36, 48 and 60 h. The phosphorylation level of p-AMPK did not change significantly. n = 6. (<b>B</b>) ROS level was recorded every half an hour after trehalose treatment (50 mM), the data representing immunofluorescence intensity within 2.5 h were shown (n = 6). No significant changes were noted.</p

Trehalose decreased PAN-induced apoptosis in human podocytes.

<p>Podocyte were treated with PAN (30 µg/ml) or/and Trehalose (50 mM) for 48 h. (<b>A</b>) Trehalose induced autophagy in PAN-treated human podocytes. The expression of LC3-II slightly increased after 48 h PAN treatment, while it dramatically up-regulated in Tre and PAN+ Tre groups. Representative immunoblot images were shown along with the statistical results. **<i>p</i><0.01 versus CON, n = 6. (<b>B–C</b>) The findings of (A) were confirmed by LC3 immunostaining. Obvious elevated LC3-II bright green puncta (indicated by white arrows) were visualized in trehalose-treated groups (Tre and PAN+ Tre groups), the representative images and statistical results were shown. Nuclei were stained in blue. **<i>p</i><0.01, ***<i>p</i><0.001 versus CON, n = 6. (<b>D</b>) No significant changes were observed in podocyte necrosis. LDH in culture medium of 4 groups was measured, n = 4. (<b>E</b>) Elevated apoptosis in PAN-treated podocytes was decreased by trehalose. Apoptosis was measured by flow cytometry with YO-PRO-1/PI assay. Podocyte apoptosis was induced by PAN and decreased significantly by trehalose. *<i>p</i><0.05, **<i>p</i><0.01 versus CON, n = 8. (<b>F</b>) The findings of (E) were confirmed by the data of active caspase-3 measurement. The active caspase-3 positive podocytes were measured by flow cytometry. The changes pattern was similar to podocyte apoptosis measured by YO-PRO-1/PI assay. **<i>p</i><0.01 versus CON, n = 7.</p

Inhibition of trehalose-induced autophagy abolished its cytoprotective effects in preventing podocyte apoptosis.

<p>CQ (25 µM) or WT (0.2 µM) was used to inhibit podocyte autophagy which was induced by trehalose (50 mM) or trehalose (50 mM) + PAN (30 µg/ml) for 48 h. (<b>A–C</b>) CQ and WT inhibited trehalose-induced autophagy. The expression of LC3-II drastically increased in Tre+CQ and PAN+ Tre+CQ groups, while it decreased significantly in Tre+WT and PAN+ Tre+WT groups. p62 slightly decreased in PAN+ Tre group, whereas it significantly increased in Tre+CQ and Tre+WT groups. The immunoblot images were shown along with statistical data. *<i>p</i><0.05, **<i>p</i><0.01 versus Tre group, n = 7. (<b>D</b>) Necrosis increased after the inhibition of trehalose-induced autophagy. The LDH in culture medium was measured. *<i>p</i><0.05, **<i>p</i><0.01 versus PAN+Tre group, n = 6. (<b>E</b>) Podocyte apoptosis increased after the inhibition of trehalose-induced autophagy. The percentage of apoptotic podocytes was much higher in PAN+Tre+CQ and PAN+Tre+WT groups than the PAN+ Tre group. *<i>p</i><0.05, **<i>p</i><0.01 versus PAN+ Tre group, n = 7. (<b>F</b>) The percentage of active caspase-3 positive podocytes increased after inhibition of trehalose-induced autophagy. The changes in the percentage of active caspase-3 positive podocytes were similar to the data in (E). *<i>p</i><0.05, **<i>p</i><0.01 versus PAN+ Tre group, n = 8.</p

Trehalose induced autophagy in human podocytes.

<p>(<b>A</b>) The expression of LC3-II increased in a dosage dependent manner. Conditionally immortalized human podocytes were treated with 0, 10, 50 and 100 mM of trehalose (Tre) for 48 h. LC3-II was measured by Western blotting. The data (means ± SEM) was expressed as the relative changes compared with Tre-0 mM group. Representative immunoblot images were shown along with the statistical results. *<i>p</i><0.05 versus Tre-0 mM, n = 5. (<b>B</b>) LC3-II increased in a time dependent manner. Podocytes were treated with 50 mM Trehalose for 0, 12, 24, 36, 48 and 60 h. **<i>p</i><0.01, ***<i>p</i><0.001 versus Tre-0 h, n = 7. (<b>C–D</b>) LC3-II puncta increased after trehalose treatment. LC3 immunostaining in podocytes was performed at 0, 12, 24, 36, 48 and 60 h after trehalose treatment (50 mM). Significant increased green bright puncta (indicated by white arrows) can be observed in cytoplasm after 48 h-trehalose treatment. The representative LC3 immunostaining images were shown along with statistical results from 6 independent experiments. **<i>p</i><0.01, ***<i>p</i><0.001 versus Tre-0 h. Podocyte nuclei were stained with DAPI (blue). (<b>E</b>) The expression of Atg5 was up-regulated in trehalose-treated podocytes (50 mM). Podocytes were treated with 50 mM Trehalose for 0, 12, 24, 36, 48 and 60 h. The expression of Atg5 significantly increased at the time point of 60 h. **<i>p</i><0.01 versus Tre-0 h, n = 5.</p