[Therapeutic potential of targeting SIRT1 for the treatment of Alzheimer's disease].

Silent information regulator 1 (SIRT1) is one of the seven mammalian proteins of the sirtuin family of NAD+-dependent deacetylases. SIRT1 plays a pivotal role in neuroprotection and ongoing research has uncovered a mechanism by which SIRT1 may exert a neuroprotective effect on Alzheimer's disease (AD). Growing evidence demonstrates that SIRT1 regulates many pathological processes including amyloid-ß precursor protein (APP) processing, neuroinflammation, neurodegeneration, and mitochondrial dysfunction. SIRT1 has recently received enormous attention, and pharmacological or transgenic approaches to activate the sirtuin pathway have shown promising results in the experimental models of AD. In the present review, we delineate the role of SIRT1 in AD from a disease-centered perspective and provides an up-to-date overview of the SIRT1 modulators and their potential as effective therapeutics in AD.

MicroRNA-486 regulates normal erythropoiesis and enhances growth and modulates drug response in CML progenitors.

MicroRNAs (miRNAs) are key regulators of hematopoietic cell differentiation and may contribute to altered growth of leukemic stem cells. Using microarray-based miRNA profiling, we found that miRNA 486 (miR-486) is significantly upregulated in chronic myeloid leukemia (CML) compared with normal CD34(+) cells, particularly in the megakaryocyte-erythroid progenitor population. miR-486-5p expression increased during erythroid differentiation of both CML and normal CD34(+) cells. Ectopic miR-486-5p expression enhanced in vitro erythroid differentiation of normal CD34(+) cells, whereas miR-486-5p inhibition suppressed normal CD34(+) cell growth in vitro and in vivo and inhibited erythroid differentiation and erythroid cell survival. The effects of miR-486-5p on hematopoietic cell growth and survival are mediated at least in part via regulation of AKT signaling and FOXO1 expression. Using gene expression and bioinformatics analysis, together with functional screening, we identified several novel miR-486-5p target genes that may modulate erythroid differentiation. We further show that increased miR-486-5p expression in CML progenitors is related to both kinase-dependent and kinase-independent mechanisms. Inhibition of miR-486-5p reduced CML progenitor growth and enhanced apoptosis following imatinib treatment. In conclusion, our studies reveal a novel role for miR-486-5p in regulating normal hematopoiesis and of BCR-ABL-induced miR-486-5p overexpression in modulating CML progenitor growth, survival, and drug sensitivity.

Ptpmt1 induced by HIF-2α regulates the proliferation and glucose metabolism in erythroleukemia cells.

Hypoxia provokes metabolism misbalance, mitochondrial dysfunction and oxidative stress in both human and animal cells. However, the mechanisms which hypoxia causes mitochondrial dysfunction and energy metabolism misbalance still remain unclear. In this study, we presented evidence that mitochondrial phosphatase Ptpmt1 is a hypoxia response molecule that regulates cell proliferation, survival and glucose metabolism in human erythroleukemia TF-1 cells. Exposure to hypoxia or DFO treatment results in upregulation of HIF1-α, HIF-2α and Ptpmt1. Only inhibition of HIF-2α by shRNA transduction reduces Ptpmt1 expression in TF-1 cells under hypoxia. Ptpmt1 inhibitor suppresses the growth and induces apoptosis of TF-1 cells. Furthermore, we demonstrated that Ptpmt1 inhibition reduces the Glut1 and Glut3 expression and decreases the glucose consumption in TF-1 cells. In additional, Ptpmt1 knockdown also results in the mitochondrial dysfunction determined by JC1 staining. These results delineate a key role for HIF-2α-induced Ptpmt1 upregulation in proliferation, survival and glucose metabolism of erythroleukemia cells. It is indicated that Ptpmt1 plays important roles in hypoxia-induced cell metabolism and mitochondrial dysfunction.

SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling.

SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-кB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM.

[Assessment of Function of a Single Limb after Injury].

OBJECTIVE: To explore the method for the objective evaluation of single limb function after in- jury in forensic medical practice. METHODS: The score of activities of daily living (ADL) were graded for a single limb function after injury from 47 cases. All cases were simultaneously evaluated using the different methods including Fugl-Meyer motor function assessment (FMA), weighting, look-up table (LUT). The correlation were compared between ADL and the other three methods. RESULTS: Injured part and the score using the three methods were correlated with ADL score (P < 0.05). The correlation coeffi- cient (|r| value) showed highest using LUT method, and lowest using FMA method. CONCLUSION: The loss function of limb is affected by the injuried parts. The methods of FMA, weighting and LUT show a good accuracy for evaluating the limb function after injury and the correlation presents higher using LUT method.

Bromodomain and extra-terminal inhibitors emerge as potential therapeutic avenues for gastrointestinal cancers.

Gastrointestinal (GI) cancers, including colorectal cancer, pancreatic cancer, liver cancer and gastric cancer, are severe social burdens due to high incidence and mortality rates. Bromodomain and extra-terminal (BET) proteins are epigenetic readers consisting of four conserved members (BRD2, BRD3, BRD4 and BRDT). BET family perform pivotal roles in tumorigenesis through transcriptional regulation, thereby emerging as potential therapeutic targets. BET inhibitors, disrupting the interaction between BET proteins and acetylated lysines, have been reported to suppress tumor initiation and progression in most of GI cancers. In this review, we will demonstrate how BET proteins participate in the GI cancers progression and highlight the therapeutic potential of targeting BET proteins for GI cancers treatment.

Comparison of CD146 +/- mesenchymal stem cells in improving premature ovarian failure.

BACKGROUND: Mesenchymal stem cells (MSCs) are a heterogeneous group of subpopulations with differentially expressed surface markers. CD146 + MSCs correlate with high therapeutic and secretory potency. However, their therapeutic efficacy and mechanisms in premature ovarian failure (POF) have not been explored. METHODS: The umbilical cord (UC)-derived CD146 +/- MSCs were sorted using magnetic beads. The proliferation of MSCs was assayed by dye670 staining and flow cytometry. A mouse POF model was established by injection of cyclophosphamide and busulfan, followed by treatment with CD146 +/- MSCs. The therapeutic effect of CD146 +/- MSCs was evaluated based on body weight, hormone levels, follicle count and reproductive ability. Differential gene expression was identified by mRNA sequencing and validated by RT-PCR. The lymphocyte percentage was detected by flow cytometry. RESULTS: CD146 +/- MSCs had similar morphology and surface marker expression. However, CD146 + MSCs exhibited a significantly stronger proliferation ability. Gene profiles revealed that CD146 + MSCs had a lower levels of immunoregulatory factor expression. CD146 + MSCs exhibited a stronger ability to inhibit T cell proliferation. CD146 +/- MSCs treatment markedly restored FSH and E2 hormone secretion level, reduced follicular atresia, and increased sinus follicle numbers in a mouse POF model. The recovery function of CD146 + MSCs in a reproductive assay was slightly improved than that of CD146 - MSCs. Ovary mRNA sequencing data indicated that UC-MSCs therapy improved ovarian endocrine locally, which was through PPAR and cholesterol metabolism pathways. The percentages of CD3, CD4, and CD8 lymphocytes were significantly reduced in the POF group compared to the control group. CD146 + MSCs treatment significantly reversed the changes in lymphocyte percentages. Meanwhile, CD146 - MSCs could not improve the decrease in CD4/8 ratio induced by chemotherapy. CONCLUSION: UC-MSCs therapy improved premature ovarian failure significantly. CD146 +/- MSCs both had similar therapeutic effects in repairing reproductive ability. CD146 + MSCs had advantages in modulating immunology and cell proliferation characteristics.

Sphingosine-1-phosphate induces human endothelial VEGF and MMP-2 production via transcription factor ZNF580: novel insights into angiogenesis.

Sphingosine-1-phosphate (S1P)-induced migration and proliferation of endothelial cells are critical for angiogenesis. C2H2-zinc finger (ZNF) proteins usually play an essential role in altering gene expression and regulating the angiogenesis. The aim of this study is to investigate whether a novel human C2H2-zinc finger gene ZNF580 (Gene ID: 51157) is involved in the migration and proliferation of endothelial cells stimulated by S1P. Our study shows that EAhy926 endothelial cells express S1P1, S1P3 and S1P5 receptors. Furthermore, S1P upregulates both ZNF580 mRNA and protein levels in a concentration- and time-dependent manner. SB203580, the specific inhibitor of the p38 mitogen-activated protein kinase (p38 MAPK) pathway, blocks the S1P-induced upregulation of ZNF580. Moreover, overexpression/downexpression of ZNF580 in EAhy926 cells leads to the enhancement/decrease of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) expression as well as the migration and proliferation of EAhy926 endothelial cells. These results elucidate the important role that ZNF580 plays in the process of migration and proliferation of endothelial cells, which provides a foundation for a novel approach to regulate angiogenesis.

[Effects of Exosomes Derived from miR-486 Gene Modified Umbilical Cord Mesenchymal Stem Cells on Biological Characteristics of Rat Cardiomyocytes].

OBJECTIVE: To investigate the effects of exosomes derived from miR-486 gene-modified umbilical cord mesenchymal stem cells (UC-MSCs) on biological characteristics of rat cardiomyocytes. METHODS: The human umbilical cord mesenchymal stem cells (UC-MSCs) were isolated and cultured, then the immunophenotypes and ability of osteogenic and adipogenic differentiation of UC-MSC were identified. The structure of exosomes was observed by electron microscopy; the effect of exosomes on cell migration was detected by transwell cell migration test; the miR-486 high expression of UC-MSC was mediated by using recombinant adenovirus vector, moreover the UC-MSC with high expression of miR-486 were identified by qPT-PCR. The exosomes were isolated from cell culture supernatant by ultracentrifugation and the miR-486 expression level of UC MSC exosomes was detected by qRT-PCR. The effect of exosomes on the proliferation of cardiomyocytes was evaluated by Dye670 marking. The H2O2-induced cardiomyocyte apoptosis model was established, and the effect of exosomes on apoptosis of cardiomyocytes was detected by flow cytometry with Annexin V/PI double staining. RESULTS: The exosomes derived from UC-MSCs had the diameter between 40-100 nm and double membrane stracture. The recombinant adenovirus could effectively mediate the expression of miR-486 in UC-MSC, and the expression level of miR-486 in exosomes of miR-486-modified UC-MSC significantly increased. The exosomes with miR-486 high expression possessed the pro-proliferation and pro-migration effects on cardiomyocytes, moreover the preventive effect on apoptosis of cardiomyocytes. CONCLUSION: The exosomes derived from UC-MSC and accompamied by high expression of miR-486 can promote the proliferation and migration of cardio myocytes, yet can prevent the apoptosis of cardiomyocytes.

[Influencing factors of psychopath's civil litigation].

OBJECTIVE: To explore the influencing factors of schizophrenic patient's capability in civil litigation, and to establish the base of quantitative study about execution of civil litigation. METHODS: To study questionnaires completed from patients with and without civil litigation capabilities and to determine the influencing factors from medical and forensic aspects. RESULTS: One hundred patients were admitted to the study and were divided into two groups based on capability in civil litigation. There were significant differences in psychiatric and legal aspects between the groups. CONCLUSION: Capability of schizophrenic patients in perusing civil litigation had been impaired or even complete lost.

[Research Advance on Promoting Angiogenesis of Mesenchymal Stem Cells-Review].

Mesenchymal stem cells (MSC) possess important biological characteristics of tissue repair and regeneration. MSC exert the properties promoting endogenous angiogenesis and have been widely applied in treatment of ischemia diseases. The therapeutic potency of MSC for ischemia diseases is owing to their secretion of angiogenic growth factors and release of exosomes. MSC promote angiogenesis stronger in hypoxia environment, and their miRNA played an important role in mediating regulation. This review summarizes recent advances in treatment of angiogenesis using MSC and their mechanisms. The angiogenic activities of MSC under hypoxia condition and their regulation by a miRNA network were discussed.

[Roles of SPK in Regulation of Hypoxia Induced Proliferation and Glucose Consume of Leukemia Cells].

OBJECTIVE: To clarify the roles of SPK pathway in the regulation of proliferation, survival and glucose consume of human erythroleukemia TF-1 cells. METHODS: The interfering in SPK expression of TF-1 cells was performed using leutivirus vector-mediated shRNA, the interference efficacy of SPK in TF-1 cells was detected by RT-qPCR and Western blot, the viability of TF-1 cell proliferation was detected by using CCK-8 method, the apoptosis of TF-1 cells was determined by flow cytmetry with Annexin V staining. RESULTS: Hypoxia up-regulated the expression of HIF-1α, HIF-2α, and SPK in TF-1 cells. SPK treatment resulted in reduced proliferation and induced apoptosis in TF-1 cells. Furthermore, knockdown of the SPK significantly reduced utilization and consumption of glucose. CONCLUSION: The SPK is key signalling molecule involved in regulation of hypoxia-induced proliferation and glucose metabolism in TF-1 cells, and plays an important rote in proliferation and energy metabolism of leukemia cells.

The epigenetically-regulated miR-34a targeting c-SRC suppresses RAF/MEK/ERK signaling pathway in K-562 cells.

Previous reports show that miR-34a suppressed K-562 cell proliferation and contributed to megakaryocytic differentiation of K-562 cells. Here, we reported that miR-34a, a tumor suppressor gene, is down-regulated in the K-562 cells and chronic myeloid leukemia (CML) patients due to aberrant DNA hypermethylation. c-SRC is a target of miR-34a. Restoring miR-34a expression resulted in down-regulation of c-SRC and phosphorylated (Tyr416) c-SRC protein in K-562 cells, which consequently triggered suppression of the RAF/MEK/ERK signaling pathway to decrease cell proliferation.

Mismatch negativity, social cognition, and functional outcomes in patients after traumatic brain injury.

Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocognition with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, respectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most significant positive correlations were found between mismatch negativity in the fronto-central region and measures of functional outcomes. The most significant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positively associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental findings suggest that mismatch negativity might efficiently reflect functional outcomes in patients after traumatic brain injury.

Effects of fluoride-ion-implanted titanium surface on the cytocompatibility in vitro and osseointegatation in vivo for dental implant applications.

As an attractive technique for the improvement of biomaterials, Plasma immersion ion implantation (PIII) has been applied to modifying the titanium material for dental implant application. The present study investigated the cytocompatibility and early osseointegration of fluoride-ion-implanted titanium (F-Ti) surface and implants, both characterizing in their composition of titanium oxide and titanium fluoride. The cytocompatibility of F-Ti was evaluated in vitro by using scanning electron microscope, Cell Counting Kit-8 assay, alkaline phosphatase activity assay, and quantitative real-time polymerase chain reaction. The results showed that the F-Ti weakened the effects that Porphyromonas gingivalis exerted on the MG-63 cells in terms of morphology, proliferation, differentiation, and genetic expression when MG-63 cells and Porphyromonas gingivalis were co-cultured on the surface of F-Ti. Meanwhile, the osteogenic activity of F-Ti implants was assessed in vivo via evaluating the histological morphology and estimating histomorphometric parameters. The analysis of toluidine blue staining indicated that the new bone was more mature in subjects with F-Ti group, which exhibited the Haversian system, and the mean bone-implant contact value of F-Ti group was slightly higher than that of cp-Ti group (p>0.05). Fluorescence bands were wider and brighter in the F-Ti group, and the intensity of fluorochromes deposited at the sites of mineralized bone formation was significantly higher for F-Ti surfaces than for cp-Ti surfaces, within the 2nd, 3rd and 4th weeks (p<0.05). An indication is that the fluoride modified titanium can promote cytocompatibility and early osseointegration, thus providing a promising alternative for clinical use.

HGF Gene Modification in Mesenchymal Stem Cells Reduces Radiation-Induced Intestinal Injury by Modulating Immunity.

BACKGROUND: Effective therapeutic strategies to address intestinal complications after radiation exposure are currently lacking. Mesenchymal stem cells (MSCs), which display the ability to repair the injured intestine, have been considered as delivery vehicles for repair genes. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF)-gene-modified MSCs on radiation-induced intestinal injury (RIII). METHODS: Female 6- to 8-week-old mice were radiated locally at the abdomen with a single 13-Gy dose of radiation and then treated with saline control, Ad-HGF or Ad-Null-modified MSCs therapy. The transient engraftment of human MSCs was detected via real-time PCR and immunostaining. The therapeutic effects of non- and HGF-modified MSCs were evaluated via FACS to determine the lymphocyte immunophenotypes; via ELISA to measure cytokine expression; via immunostaining to determine tight junction protein expression; via PCNA staining to examine intestinal epithelial cell proliferation; and via TUNEL staining to detect intestinal epithelial cell apoptosis. RESULTS: The histopathological recovery of the radiation-injured intestine was significantly enhanced following non- or HGF-modified MSCs treatment. Importantly, the radiation-induced immunophenotypic disorders of the mesenteric lymph nodes and Peyer's patches were attenuated in both MSCs-treated groups. Treatment with HGF-modified MSCs reduced the expression and secretion of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α) and interferon-gamma (IFN-γ), increased the expression of the anti-inflammatory cytokine IL-10 and the tight junction protein ZO-1, and promoted the proliferation and reduced the apoptosis of intestinal epithelial cells. CONCLUSIONS: Treatment of RIII with HGF-gene-modified MSCs reduces local inflammation and promotes the recovery of small intestinal histopathology in a mouse model. These findings might provide an effective therapeutic strategy for RIII.

[Effect of aurora inhibitor VX-680 on proliferation and apoptosis of CML cells].

This study was aimed to explore the effect of VX-680, an aurora inhibitor, on proliferation and apoptosis of K562, KCL22 cell lines and CD34⁺ cells from chronic myeloid leukemia (CML) patients in vitro. The proliferation of K562 and KCL22 cell was detected by CCK-8 method. Apoptosis of cells was detected by Annexin V-PI labeling and flow cytometry. The colony forming ability of bone marrow CD34⁺ cells derived from CML patients and donors was determined by the colony forming test. The results showed that the treatment of K562, KCL22 and CML CD34⁺ cells with VX-680 of 20-100 nmol/L for 3 days could obviously inhibit the cell proliferation in a concentration-dependent manner (P < 0.01). VX-680 treatment significantly induced apoptosis of K562 and KCL22 cells. Compared to bone marrow CD34⁺ cells derived from the healthy donors, the colony forming ability of CML CD34⁺ cells derived from bone marrow of CML patients was remarkably reduced (P < 0.01). It is concluded that VX-680, an aurora inhibitor, can inhibit the proliferation and induce apoptosis of CML cells in vitro.

[Effect of microRNA-17-92 cluster on the biological characteristics of K562 cells and its mechanisms].

The objective of this study was to explore the effects of microRNA-17-92 on the biological characteristics of K562 cells. The expression of miR-17-92 in K562 cells transfected with miRNA-17-92 mimic was detected by real time PCR. The effect of microRNA-17-92 on K562 cell proliferation was detected by CCK-8 method. Apoptosis of K562 cells was detected by Annexin V-PI labeling. Cell cycle distribution was determined by using flow cytometry. Western blot was performed to determine the protein levels of Crk. The results indicated that the transfection with miR-17-92 mimic increased expression of mature miR-17-92 in K562 cells. Compared with control group, cell proliferation and cell amount in S-phase of miR-17-92 mimic transfected group significantly increased, cell apoptosis decreased. The expression of signal connector protein Crk was greatly up-regulated in miR-17-92-mimic-transfected K562 cells. It is concluded that miR-17-92 can promote proliferation, inhibit apoptosis and regulate the cell cycle of K562 cells.

Activation of sphingosine kinase mediates suppressive effect of interleukin-6 on human multiple myeloma cell apoptosis.

Interleukin 6 (IL-6) influences the growth and survival of multiple myeloma (MM) cells via the activation of multiple signalling cascades. Although sphingosine kinase (SPHK) signalling is known to play important roles in the regulation of cell proliferation and apoptosis, the role of SPHK activation in IL-6 signalling and in the pathology of MM remains unclear. This study found that IL-6 activated SPHK in MM cells, which mediates the suppressive effects of IL-6 on MM cell apoptosis. Both MM cell lines and primary MM cells constitutively expressed SPHK, and treatment of MM cells with IL-6 resulted in activation of SPHK in a concentration-dependent manner. Specific inhibitors of the phosphatidylinositol-3 kinase and extracellular signal-regulated kinase/mitogen-activated protein kinase pathways blocked the IL-6-induced activation of SPHK. It was further demonstrated that IL-6-induced activation of SPHK inhibited dexamethasone-induced apoptosis of MM cells. IL-6 stimulation or retroviral-mediated overexpression of SPHK1 in MM cells resulted in increased intracellular SPHK activity and upregulation of myeloid cell leukaemia-1 (Mcl-1), leading to increased cell proliferation and survival. Conversely, inhibition of SPHK1 by small interfering RNA reduced IL-6-induced upregulation of Mcl-1 and blocked the suppressive effect of IL-6 on MM cell apoptosis. Taken together, these results delineate a key role for SPHK activation in IL-6-induced proliferation and survival of MM cells, and suggest that SPHK may be a potential new therapeutic target in MM.