Computed tomography-determined skeletal muscle density predicts 3-year mortality in initial-dialysis patients in China.

BACKGROUND: Skeletal muscle mass and quality assessed by computed tomography (CT) images of the third lumbar vertebra (L3) level have been established as risk factors for poor clinical outcomes in several illnesses, but the relevance for dialysis patients is unclear. A few studies have suggested a correlation between CT-determined skeletal muscle mass and quality at the first lumbar vertebra (L1) level and adverse outcomes. Generally, chest CT does not reach beyond L1. We aimed to determine whether opportunistic CT scan (chest CT)-determined skeletal muscle mass and quality at L1 are associated with mortality in initial-dialysis patients. METHODS: This 3-year multicentric retrospective study included initial-dialysis patients from four centres between 2014 and 2017 in China. Unenhanced CT images of the L1 and L3 levels were obtained to assess skeletal muscle mass [by skeletal muscle index, (SMI), cm2 /m2 ] and quality [by skeletal muscle density (SMD), HU]. Skeletal muscle measures at L1 were compared with those at L3. The sex-specific optimal cutoff values of L1 SMI and L1 SMD were determined in relation to all-cause mortality. The outcomes were all-cause death and cardiac death. Cox regression models were applied to investigate the risk factors for death. RESULTS: A total of 485 patients were enrolled, of whom 257 had both L1 and L3 images. Pearson's correlation coefficient between L1 and L3 SMI was 0.84 (P < 0.001), and that between L1 and L3 SMD was 0.90 (P < 0.001). No significant association between L1 SMI and mortality was observed (P > 0.05). Low L1 SMD (n = 280, 57.73%) was diagnosed based on the optimal cutoff value (<39.56 HU for males and <33.06 HU for females). Multivariate regression analysis revealed that the low L1 SMD group had higher risks of all-cause death (hazard ratio 1.80; 95% confidence interval 1.05-3.11, P = 0.034) and cardiac death (hazard ratio 3.74; 95% confidence interval 1.43-9.79, P = 0.007). CONCLUSIONS: In initial-dialysis patients, there is high agreement between the L1 and L3 measures for SMI and SMD. Low SMD measured at L1, but not low SMI, is an independent predictor of both all-cause death and cardiac death.

Inhibition of glioblastoma progression by Urolithin A in vitro and in vivo by regulating Sirt1-FOXO1 axis via ERK/AKT signaling pathways.

Glioblastoma (GBM) is the most universal and devastating primary intracranial neoplasm in the central nervous system. Urolithin A (UA) possesses many pharmacological and biological activities, but its function in GBM is not clear. CCK-8 and colony formation test were used to measure the anti-proliferative potency of UA against GBM cells. Flow cytometry was applied to evaluate cell cycle arrest and apoptosis of U251 and U118 MG cells upon UA incubation. Quantitative real-time PCR and western blotting were conducted to test the regulatory effect of UA on the expression of Sirt1 and FOXO1. Immunodeficient mice were implanted with GBM cells for in vivo validation of the anti-cancer effect of UA. We found UA repressed the proliferation, migration and invasion of glioblastoma cells, while also inhibiting the induction of colony formation ability and epithelial to mesenchymal transition (EMT) in a time- or dose-dependent manner. The does-dependent relationship of UA inducing the cell cycle arrest and apoptosis of glioblastoma cells was identified. Furthermore, UA could enhance the expression levels of Sirt1 and FOXO1 and the knockdown of Sirt1 blocked the inhibitory effects of UA on the proliferation and migration of glioblastoma cells and correspondingly modified the expression level of FOXO1. Overexpression of Sirt1 restored the despaired inhibitory effect of UA induced by Sirt1 knockout on the proliferation and migration of glioblastoma cells. In animal experiments, UA decreased the tumor size and weight of glioblastoma in xenograft nude mice and promoted the expression of Sirt1 and FOXO1 in transplanted tumors. Our findings presented in this study indicate that UA exerts a repressive effect on glioblastoma cells in vivo and in vitro by regulating the Sirt1-FOXO1 axis via the ERK and AKT pathways, indicating that UA is a new novel therapeutic candidate for the treatment of glioblastoma.

AdipoRon improves cognitive dysfunction of Alzheimer's disease and rescues impaired neural stem cell proliferation through AdipoR1/AMPK pathway.

Adult neurogenesis in hippocampus dentate gyrus (DG) is associated with the etiology on the early stage of Alzheimer's disease (AD). Factors that affect adult hippocampal neurogenesis have been shown to contribute to the neuropathology of AD. Adiponectin, a peptide hormone secreted by adipocytes, plays a critical role in insulin sensitizing, anti-inflammatory, and anti-diabetic effects in peripheral tissues. We previously showed that AdipoRon, as an agonist of adiponectin, promotes neurite outgrowth under ischemia. However, the role of AdipoRon on neural stem cells (NSCs) proliferation and cognitive dysfunction in the early stage of AD remains unknown. In this study, we investigated the role of AdipoRon on cognitive dysfunction and deficits of NSCs proliferation in AD. The in vivo study showed that AdipoRon improved either cognitive dysfunction or impaired NSCs proliferation in hippocampus DG region in APP/PS1 transgenic (Tg) mice. In addition, AdipoRon treatment also suppressed the ß-amyloid (Aß) deposition and inhibited ß-secretase 1(BACE1) expression in both cortex and hippocampus of APP/PS1 Tg mice. The in vitro study further suggested that AdipoRon significantly alleviated Aß-induced cell viability and neuronal morphology in primary neurons. Both AdipoR1 silencing and compound C, inhibitor of AMPK, completely abolished the effect of AdipoRon. Interestingly, AdipoRon also protected the dissipation of the ΔΨm caused by Aß toxicity in primary neurons, which was reversed by compound C. In NE-4C NSCs, AdipoRon significantly promoted the Aß-induced impaired cell proliferation through AdipoR1/AMPK/CREB pathway. Furthermore, inhibition of AMPK by compound C also reversed the promotive effects of AdipoRon on cognition and proliferation of NSCs of APP/PS1 Tg mice, suggesting a AMPK-dependent mechanism by AdipoRon in AD in vivo. Taken together, these results suggested that AdipoRon alleviated the cognitive dysfunction of AD mice, inhibited the Aß deposition by inhibiting BACE1 expression and promoted the impaired hippocampal NSCs proliferation on the early stage in vivo. The mechanisms involved activation of AdipoR1/AMPK pathway. Therefore, AdipoRon might be a potential candidate for the treatment of AD on the early stage.

Cloning and high expression of hbFGF with a new strategy.

Computer program DNASIS v2.5 was used to help designing the site-directed mutations for optimizing the expression of hbFGF in E. coli. The secondary structure of the translation initiation region (TIR) is a determinant factor for translation initiation rate, meanwhile, codon preference plays an important role, too. According to the two principles, 4 sites in 5' end of hbFGF cDNA were definitely changed, and another 4 sites randomly changed. These mutations will lead to potential variation in the secondary structure of TIR. Then computer program DNASIS v2.5 was utilized to analyse the total 32 TIR sequences resulted from the combination of the 4 randomly mutated sites. Ten sequences with highest free formation energy (delta G0) were chosen for subsequent cloning. By PCR using synthetic primers containing the 8 changed sites described above, ten hbFGF cDNA were amplified and cloned to pET-3c respectively. E. coli strain BL21 (DE3) was transformed and induced to express recombinant hbFGF. Two high-expression clones were obtained by SDS-PAGE and MTT assay, indicating that computer program-aided design for optimizing expression of foreign genes in E. coli is useful.