High-salt diet induces dyslipidemia through the SREBP2/PCSK9 pathway in dahl salt-sensitive rats.

A high-salt diet is known to increase serum cholesterol levels; however, the underlying mechanism of salt-induced dyslipidemia in patients with salt-sensitivity remains poorly understood. We aimed to investigate whether high-salt diet (HSD) can induce dyslipidemia and elucidate the underlying mechanism of salt-induced dyslipidemia in Dahl salt-sensitive (SS) rats. Metabolomic and biochemical analyses revealed that the consumption of an HSD (8 % NaCl) significantly increased the serum levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in SS rats. The enzyme-linked immunosorbent assay demonstrated an increase in circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) levels, accompanied by a decrease in hepatic low-density lipoprotein receptor (LDLR) levels due to HSD consumption. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis revealed that HSD consumption activated sterol regulatory element-binding protein-2 (SREBP2) expression in the liver and kidney, resulting in upregulation of PCSK9 at the transcriptional level in the liver and at the translational level in the kidney, ultimately increasing circulating PCSK9 levels. The combined effects of HSD on the liver and kidney contributed to the development of hypercholesterolemia. Furthermore, an in vitro assay confirmed that high-salt exposure led to an increase in the protein expression of SREBP2 and PCSK9 secretion, thereby reducing low-density lipoprotein (LDL) uptake. This study, for the first time, shows that an HSD induces dyslipidemia through activation of the SREBP2/PCSK9 pathway, providing new insights into the prevention and treatment of dyslipidemia in patients with salt sensitivity.

Elucidation of the Application of Blood Test Biomarkers to Predict Immune-Related Adverse Events in Atezolizumab-Treated NSCLC Patients Using Machine Learning Methods.

Background: Development of severe immune-related adverse events (irAEs) is a major predicament to stop treatment with immune checkpoint inhibitors, even though tumor progression is suppressed. However, no effective early phase biomarker has been established to predict irAE until now. Method: This study retrospectively used the data of four international, multi-center clinical trials to investigate the application of blood test biomarkers to predict irAEs in atezolizumab-treated advanced non-small cell lung cancer (NSCLC) patients. Seven machine learning methods were exploited to dissect the importance score of 21 blood test biomarkers after 1,000 simulations by the training cohort consisting of 80%, 70%, and 60% of the combined cohort with 1,320 eligible patients. Results: XGBoost and LASSO exhibited the best performance in this study with relatively higher consistency between the training and test cohorts. The best area under the curve (AUC) was obtained by a 10-biomarker panel using the XGBoost method for the 8:2 training:test cohort ratio (training cohort AUC = 0.692, test cohort AUC = 0.681). This panel could be further narrowed down to a three-biomarker panel consisting of C-reactive protein (CRP), platelet-to-lymphocyte ratio (PLR), and thyroid-stimulating hormone (TSH) with a small median AUC difference using the XGBoost method [for the 8:2 training:test cohort ratio, training cohort AUC difference = -0.035 (p < 0.0001), and test cohort AUC difference = 0.001 (p=0.965)]. Conclusion: Blood test biomarkers currently do not have sufficient predictive power to predict irAE development in atezolizumab-treated advanced NSCLC patients. Nevertheless, biomarkers related to adaptive immunity and liver or thyroid dysfunction warrant further investigation.

Identification of an endogenous retroviral signature to predict anti-PD1 response in advanced clear cell renal cell carcinoma: an integrated analysis of three clinical trials.

Background: Endogenous retrovirus (ERV) elements are genomic footprints of ancestral retroviral infections within the human genome. Previous studies have demonstrated that dysregulated ERV transcription level is associated with immune cell infiltration in cancers, but the association between ERV expression and programmed cell death protein 1 (PD-1) blockade response is currently unraveled for solid cancers, such as advanced clear cell renal cell carcinoma (ccRCC). Methods: ERV mRNA profiles were obtained from three clinical trials of ccRCC where the patients were treated with anti-PD-1 (CM-009, CM-010, CM-025, and TCGA-KIRC data). Patients treated with nivolumab were divided into training and test cohort, while the TCGA-KIRC cohort was used as an external validation. Univariate Cox regression analysis and least absolute shrinkage and selection operator regression were used to establish the signature. Immune cell infiltration analysis and gene set enrichment analysis were performed to explore potential biological mechanisms. Results: An ERV signature was established based on nine ERV expression patterns. In the training cohort, the median overall survival in the low- and high-risk group was 45.2 and 19.6 months [hazard ratio (HR) = 0.49, 0.32-0.75, p < 0.001], respectively. The results were confirmed in the test (HR = 0.41, 0.20-0.83, p = 0.013), and in the TCGA-KIRC cohort (HR = 0.55, 0.34-0.90, p = 0.017). Moreover, in the CM-025 cohort, the low-risk group that received nivolumab had a more favorable survival compared with those that received the mTOR inhibitor everolimus, while no significant differences were observed in the high-risk group. CD8+ T cells were enriched in the low-risk group, while immune suppressive pathways were suppressed. Conclusion: The newly identified ERV signature is not only a prognostic, but also a predictive biomarker for advanced ccRCC patients who received anti-PD-1 therapy, which can guide personalized treatment in cancer patients in the future.

Lower androgen levels promote abnormal cartilage development in female patients with adolescent idiopathic scoliosis.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a disease characterized by changes in the three-dimensional structure of the spine. Studies have shown that the development of AIS might be associated with genetic, biomechanics, endocrine factors and abnormal bone or cartilage development. METHODS: Blood samples collected from 301 female patients (161 females with AIS and 140 females without AIS) were used for genotyping. Forty-eight serum samples from 161 females with AIS and 40 serum samples from 140 females without AIS were subjected to enzyme-linked immunosorbent assays (ELISAs). We also evaluated 32 facet joints (18 females with AIS and 14 females without AIS from the 301 female patients) using immunohistochemistry, Western blotting, and isolation of human primary chondrocytes, among other methods. We treated the AIS primary chondrocytes with dihydrotestosterone (DHT) to verify the relationship among androgen, the androgen receptor (AR), and its downstream pathway proteins. RESULTS: The serum androgen level in the AIS group was significantly decreased (1.94±0.09 vs. 2.284±0.103) compared with that in the non-AIS (control) group. The single nucleotide polymorphism genotyping results showed that the mutation rates of rs6259 between the AIS and control groups were significantly different (G/G genotype: 48.4% vs. 42.1%, G/A genotype: 40.4% vs. 35.7%, P<0.05). The levels of interleukin (IL)-6 and metalloproteinase (MMP)-13 were increased in the cartilage of AIS patients, and these patients also exhibited decreased AR levels. The cell experiment results showed that androgen reduced the degree of abnormal cartilage development in female AIS patients through the AR/IL-6/signal transducer and activator of transcription 3 (STAT3) signaling pathway. CONCLUSIONS: Our study provides a new perspective on the pathogenesis of AIS and indicates that decreased androgen levels in female AIS patients play a potential role in the development of AIS via the AR/IL-6/STAT3 signaling pathway.

rs6127698 polymorphism in the MC3R gene and susceptibility to multifocal tuberculosis in southern Chinese Han population.

OBJECTIVE: To investigate the relationship between melanocortin-3 receptor (MC3R) gene polymorphism and tuberculosis (TB) susceptibility in Han population in southern China. METHODS: A total of 341 patients with TB (173 with pulmonary TB and 168 with multifocal TB) and 359 healthy controls were enrolled. Genotyping was performed by PCR and DNA sequencing, and detection of protein was performed by western blot. RESULTS: The distributions of genotype and allele frequencies of rs6127698 differed significantly between the pulmonary and multifocal TB groups, and between the multifocal TB and control groups. The GG genotype was significantly more common among multifocal TB patients than among pulmonary TB patients (P = .009) and those in the control group (P = .001) under the recessive model. GG+GT genotype was more common in multifocal TB than in pulmonary TB (P < .01) and control group (P < .01) under the dominant model. G allele was more common in multifocal TB than in pulmonary TB (P < .0167) and control group (P < .0167). Patients with multifocal TB had an increased expression of MC3R protein than healthy controls (P < .05). CONCLUSIONS: In the southern Chinese Han population, the MC3R rs6127698 polymorphism, which accompanying an increased expression of MC3R protein,was associated with susceptibility to multifocal TB. Presence of the G allele increased the risk of developing multifocal TB.

Ghrelin up-regulates cartilage-specific genes via the ERK/STAT3 pathway in chondrocytes of patients with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a severe spinal deformity that often occurs during puberty. The occurrence of AIS is suggested to be related to abnormal development of cartilage. Our previous study found increased serum ghrelin levels in AIS patients that may linked to the development of AIS. However, whether ghrelin affects cartilage in AIS patients is unclear. We used quantitative real-time PCR (qRT-PCR) and immunohistochemistry to detect the expression of cartilage-specific genes and the ghrelin receptor, growth hormone secretagogue receptor (GHSR). The mRNA and protein levels of collagen II (COLII), SOX9, AGGRECAN (ACAN) and GHSR were higher in AIS patients than in controls. In addition, the protein levels of GHSR downstream signaling pathway members p-STAT3 (Ser727), and p-ERK1/2 were increased. Furthermore, we treated chondrocytes from AIS patients with 100 nM ghrelin, the cell proliferation assay and Western blotting showed that ghrelin promotes chondrocyte proliferation and enhances COLII, SOX9, ACAN, p-ERK1/2 and p-STAT3 expression, respectively. Interestingly, all these observed alterations were abolished by ghrelin + [D-Lys3]-GHRP-6 (a ghrelin receptor inhibitor) treatment. And after U0126 (an inhibitor of ERK1/2 phosphorylation) treatment, ERK1/2 and STAT3 (Ser727) phosphorylation was simultaneously suppressed indicating that ERK1/2 is an upstream pathway protein of STAT3 (Ser727). In conclusion, ghrelin plays an important role in upregulating cartilage-specific genes on AIS primary chondrocytes by activating ERK/STAT3 signaling pathway.

Taxifolin Inhibits Receptor Activator of NF-κB Ligand-Induced Osteoclastogenesis of Human Bone Marrow-Derived Macrophages in vitro and Prevents Lipopolysaccharide-Induced Bone Loss in vivo.

It has been reported that taxifolin inhibit osteoclastogenesis in RAW264.7 cells. In our research, the inhibition effects of taxifolin on the osteoclastogenesis of human bone marrow-derived macrophages (BMMs) induced by receptor activator of NF-κB ligand (RANKL) as well as the protection effects in lipopolysaccharide-induced bone lysis mouse model have been demonstrated. In vitro, taxifolin inhibited RANKL-induced osteoclast differentiation of human BMMs without cytotoxicity. Moreover, taxifolin significantly suppressed RANKL-induced gene expression, including tartrate-resistant acid phosphatase, matrix metalloproteinase-9 nuclear factor of activated T cells 1 and cathepsin K, and F-actin ring formation. Further studies showed that taxifolin inhibit osteoclastogenesis via the suppression of the NF-κB signaling pathway. In vivo, taxifolin prevented bone loss in mouse calvarial osteolysis model. In conclusion, the results suggested that taxifolin has a therapeutic potential for osteoclastogenesis-related diseases such as osteoporosis, osteolysis, and rheumatoid arthritis.

High Ghrelin Level Predicts the Curve Progression of Adolescent Idiopathic Scoliosis Girls.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is common deformity with unknown cause. Previous studies have suggested the abnormal serum leptin and ghrelin level in AIS girls. The aim of present study was to evaluate whether the serum leptin and ghrelin level could serve as risk factor in predicting the curve progression in AIS girls. The associations between them and the physical characteristics were also investigated. MATERIALS AND METHODS: Circulating leptin and ghrelin levels from 105 AIS girls and 40 age-matched non-AIS girls were examined by enzyme-linked immunosorbent assay. The correlations between ghrelin and leptin levels and growth-related parameters (age, weight, corrected height, corrected BMI, main Cobb angle, and Risser sign) were analyzed in AIS group. Multivariate logistic regression was used to investigate factors predicting curve progression in AIS girls. RESULTS: A significantly lower leptin level (6.55 ± 2.88 vs. 8.01 ± 3.12 ng/ml, p < 0.05) and a higher ghrelin level (6.33 ± 2.46 vs. 4.46 ± 2.02 ng/ml, p < 0.05) were found in all AIS patients, as compared with normal controls. Curve progression patients had a higher ghrelin level than stable curve patients (7.61 ± 2.48 vs. 5.54 ± 2.11 ng/ml, p < 0.01); for leptin level, there was no significant difference between progression and stable group. The results of multivariate logistic stepwise regression showed that premenarche status, initial main Cobb magnitude that was more than or equal to 23°, high ghrelin level (≥7.30 ng/ml), and lower Risser grade (grades 0 to 2) were identified as risk factors in predicting curve progression. Ghrelin levels of >6.48 ng/ml were predictive for curve progression with 70.00 % sensitivity and 72.31 % specificity, and the area under the curve (AUC) was 0.741 (95 % confidence interval 0.646-0.821). CONCLUSIONS: High ghrelin level may serve as a new quantitative indicator for predicting curve progression in AIS girls.

Taxifolin enhances osteogenic differentiation of human bone marrow mesenchymal stem cells partially via NF-κB pathway.

Taxifolin, a flavonoid compound, has been reported to stimulate osteogenic differentiation in osteoblasts. The present study investigated whether taxifolin affects the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and the molecular mechanisms involved. The proliferation and osteogenic differentiation of hBMSCs in the presence of taxifolin were examined by CCK-8 assay, alkaline phosphatase (ALP) activity, ALP staining and Alizarin red staining. The expression of osteogenic differentiation markers were detected by real-time quantitative PCR (RT-PCR) analysis and western blot assay. The activation of potential related pathways was examined by luciferase reporter assay, immunofluorescence and western blot analysis. Taxifolin treatment increased osteogenic differentiation of hBMSCs without cytotoxicity. Luciferase reporter assay showed that taxifolin could not activate estrogen receptor pathway, but inhibit TNF-α-induced NF-κB signaling pathway activation in osteogenic induction condition. Moreover, the nucleus translocation of NF-κB under TNF-α treatment was inhibited by taxifolin treatment. The taxifolin-induced osteogenic differentiation effects of hBMSCs were abolished by TNF-α treatment. In conclusion, our results suggested that taxifolin could promote osteogenesis of hBMSCs, partially through antagonism of NF-κB signaling pathway.

Hemin protects against oxygen-glucose deprivation-induced apoptosis activation via neuroglobin in SH-SY5Y cells.

This study aimed to investigate the mechanism underlying the neuroprotective effect of hemin in oxygen-glucose deprivation (OGD)-treated neurons. OGD-treated SH-SY5Y cells (human neuroblastoma cells) were used in the study. The cellular viability of SH-SY5Y cells was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell apoptosis rate was determined by flow cytometry analysis with Annexin V-fluorescein isothiocyanate and propidium iodide staining with or without hemin pretreatment. Cell viability and apoptotic activation were detected after hemin administration combined with neuroglobin (Nqb), thioredoxin-1, peroxiredoxin-2, or heme oxygenase-1 siRNA transient transfection. The release of cytochrome c from mitochondria and the interaction between Ngb and cytochrome c were examined with hemin pretreatment. Hemin had a neuroprotective effect in OGD-treated SH-SY5Y cells, which was mainly mediated by the upregulation of Ngb. Moreover, the release of cytochrome c from mitochondria was inhibited by hemin-induced Ngb expression through facilitating the interaction of Ngb with cytochrome c in mitochondria. The present findings provided new insights into the neuroprotective mechanisms of hemin. It was concluded that low-dose hemin pretreatment had a neuroprotective effect in OGD-treated SH-SY5Y cells, through inhibiting cell apoptosis. The neuroprotective effects of hemin following hypoxic-ischemic neuronal damage were mainly mediated by Ngb. One underlying mechanism was hemin-induced overexpression of mitochondrial Ngb, which inhibited endogenous apoptosis via the association with cytochrome c.

[Study on Automatic Identification of Aerosols Boundary Layer Height with Local Optimum Model Based on Lidar Data].

The atmospheric aerosols have significant influence on human health, the environment and the climate system. The atmospheric boundary layer (ABL) reflects processes of the near-surface atmosphere and concentration of pollutants. Ground-based laser radar can monitor the vertical distribution of atmospheric aerosols stably and continuously. It provides dynamic information for timing observations of the ABL and environmental forecasting, if aerosols can be monitored and evaluated using lidar technology. There is a gap in the study of ABL observations during the presence of a residual layer and aerosol intrusion, as well as deficiencies in the accuracy and poor computational efficiency of the gradient method. This paper combines the physical meaning of the latter method with characteristics of a lidar timing chart and local optimum model, which based on space-time proximity. Then a polarization-Mie scattering lidar system is used to observe the vertical distribution of aerosols over time at Taihu observation site, which is in a newly developed area of the city of Wuxi, Jiangsu Province, China. Observation and analysis is carried out for two cases in terms of pollution at the end of 2012. Then corresponding estimation model was built with gradient method and local optimum model based on range-corrected signals. In the case of steady weather and mixed pollution, results of the gradient method and local optimum model were very similar. However, the gradient method has more error in the case of pollution intrusion with the residual layer. The local optimum model based on the space-time proximity theory considers vertical eigenvalues and horizontal correlations, thereby greatly reducing the effects of low clouds, signal interference, weak signals, bi-layered aerosols, and residual layer condition. Compared with the gradient method, the local optimum model had a smaller O(n) and greater stability in computer automatic identification. ABL identification in the case with the residual layer and aerosol intrusion was solved with use of lidar technology and the local optimum model. The accuracy and computational efficiency problems of the gradient method were resolved using automatic operation.

Leptin Receptor Metabolism Disorder in Primary Chondrocytes from Adolescent Idiopathic Scoliosis Girls.

To investigate the underlying mechanisms of low metabolic activity of primary chondrocytes obtained from girls with adolescent idiopathic scoliosis (AIS); AIS is a spine-deforming disease that often occurs in girls. AIS is associated with a lower bone mass than that of healthy individuals and osteopenia. Leptin was shown to play an important role in bone growth. It can also regulate the function of chondrocytes. Changes in leptin and Ob-R levels in AIS patients have been reported in several studies. The underlying mechanisms between the dysfunction of peripheral leptin signaling and abnormal chondrocytes remain unclear; The following parameters were evaluated in AIS patients and the control groups: total serum leptin levels; Ob-R expression in the plasma membrane of primary chondrocytes; JAK2 and STAT3 phosphorylation status. Then, we inhibited the lysosome and proteasome and knocked down clathrin heavy chain (CHC) expression in primary chondrocytes isolated from girls with AIS and evaluated Ob-R expression. We investigated the effects of leptin combined with a lysosome inhibitor or CHC knockdown in primary chondrocytes obtained from AIS patients; Compared with the controls, AIS patients showed similar total serum leptin levels, reduced JAK2 and STAT3 phosphorylation, and decreased cartilage matrix synthesis in the facet joint. Lower metabolic activity and lower membrane expression of Ob-R were observed in primary chondrocytes from the AIS group than in the controls. Lysosome inhibition increased the total Ob-R content but had no effect on the membrane expression of Ob-R or leptin's effects on AIS primary chondrocytes. CHC knockdown upregulated the membrane Ob-R levels and enhanced leptin's effects on AIS primary chondrocytes; The underlying mechanism of chondrocytes that are hyposensitive to leptin in some girls with AIS is low plasma membrane Ob-R expression that results from an imbalance between the rate of receptor endocytosis and the insertion of newly synthesized receptors into the membrane.

[Hyperspectral extraction of soil available nitrogen in Nan Mountain coal waste scenic spot of Jinhuagong Mine based on enter-PLSR].

Soil available nitrogen content is an important index reflecting soil fertility. It provides dynamic information for land reclamation and ecological restoration if soil available nitrogen can be monitored and evaluated using hyperspectral technology. Facing the study blank of soil available nitrogen in National Mine Park and the deficiency of poor computational efficiency of partial least squares regression (PLSR) method, the present paper presents the relationship between soil spectrum and soil available nitrogen based on spectrum curves (ranging from 350 to 2 500 nm) of 30 salinized chestnut soil samples, which were collected from southern mountain coal waste scenic spot, located in Jinhuagong mine in Datong city, Shanxi Province, China (one part of Jinhuagong national mine park). Soil reflection spectrum was mathematically manipulated into first derivative and inverse-log spectral curves, then a corresponding estimation model was built and examined by PLSR and Enter-partial least squares regression (Enter-PLSR) based on characteristic absorption. The result indicated that Enter-PLSR corresponding estimation model greatly increased the computation efficiency by reducing the number of independent variables to 12 from 122 in case of a close accuracy of PLS corresponding estimation model. By using hyperspectral technology and Enter-PLSR method, the study blank of soil available nitrogen in National Mine Park was filled. At the same time, the computation efficiency problem of PLSR was resolved.