Association between serum cotinine and α-Klotho levels among adults: Findings from the National Health and Nutrition Examination Survey 2007-2016.

INTRODUCTION: Serum cotinine is a sensitive and specific marker of tobacco smoke exposure. α-Klotho is an anti-ageing molecule, which plays an important role in several diseases. We aimed to examine the association between smoke exposure indicated by the serum cotinine and α-Klotho levels, as previous reports regarding the level of α-Klotho in smokers have been inconsistent. METHODS: This secondary dataset analysis included 9833 participants (aged 40-79 years; 47.0% females and 53.0% males) from the US National Health and Nutrition Examination Survey 2007-2016. Independent variables were serum cotinine level, age, sex, race, body mass index (BMI), and alcohol consumption. The outcome variable was serum α-Klotho level. Multiple linear regression analysis was used to examine the association between serum cotinine and α-Klotho levels. RESULTS: The serum cotinine level was negatively associated with the α-Klotho level (ß= -0.107, 95% CI: -0.155 to -0.059, p<0.0001) after adjusting for age, BMI, sex, race, and alcohol consumption. The α-Klotho level in participants with cotinine ≥3 ng/mL decreased by 44.514 pg/mL (p<0.0001) compared to that in participants with cotinine <3 ng/mL. There is a non-linear relationship between serum cotinine and α-Klotho levels. The piecewise linear models indicated a significant threshold effect between serum cotinine and α-Klotho levels. On the left of the inflection point (cotinine <130 ng/mL), the serum cotinine level increased with decreased α-Klotho level (ß= -0.519, 95% CI: -0.682 to -0.356). On the right of the inflection point (cotinine ≥130 ng/mL), the serum cotinine level increased with increased α-Klotho level (ß=0.085, 95% CI: 0.000 to 0.170). CONCLUSIONS: Based on our study results, serum cotinine level was associated with the serum α-Klotho level.

Sodium valproate sensitizes non-small lung cancer A549 cells to γδ T-cell-mediated killing through upregulating the expression of MICA.

Major histocompatibility complex (MHC) class I chain-related protein A (MICA) is involved in γδ T-cell recognition of target tumor cells. The aim of this study was to investigate the feasibility of utilization of sodium valproate (VPA), a histone deacetylase inhibitor, to sensitize non-small cell lung cancer A549 cells to γδ T-cell-mediated killing. VPA induced a dose-dependent increase in the mRNA and protein expression of MICA in A549 cells. γδ T cells showed cytotoxicity to A549 cells, which was increased by about 50% in the presence of VPA. The concomitant addition of MICA antibody significantly attenuated the VPA-mediated sensitization to γδ T-cell killing. VPA enhanced the cleavage of caspase-3 and caspase-9 in A549 cells cocultured with γδ T cells, and such enhancement was reversed by the MICA antibody. In conclusion, VPA sensitizes tumor cells to γδ T-cell-mediated cytotoxicity through the upregulation of MICA and may thus have benefits in improving γδ T-cell-based cancer immunotherapy.

The viable Mycobacterium tuberculosis H37Ra strain induces a stronger mouse macrophage response compared to the heat-inactivated H37Rv strain.

Macrophages are the target cells for Mycobacterium tuberculosis (M. tuberculosis) as well as key effector cells for clearance of this pathogen. The aim of the present study was to measure and compare the responses of mouse peritoneal macrophages following exposure to the live M. tuberculosis H37Ra and heat-inactivated H37Rv strains. In vitro phagocytosis assays indicated that the macrophages had a higher capacity to engulf the live H37Ra strain compared to the inactivated H37Rv strain. Enzyme-linked immunosorbent assay (ELISA) demonstrated that H37Ra­stimulated macrophages produced significantly increased concentrations of interleukin­12p40 (IL­12p40), tumor necrosis factor-α (TNF­α) and interferon­Î³ (IFN­Î³) compared to the untreated control cells. However, H37Rv exposure induced little to no increase in the levels of the cytokines examined. The results from ELISA were confirmed by reverse transcription-polymerase chain reaction (RT­PCR) at the mRNA level. There was a dose-dependent increase in nitric oxide (NO) and hydrogen peroxide (H2O2) production from the H37Ra­stimulated macrophages compared to the H37Rv­stimulated ones. Confocal microscopy and flow cytometric analysis indicated that the IFN­Î³­stimulated macrophages from viable H37Ra­immunized mice had an enhanced surface expression of CD40 ligand (CD40L) compared to those from inactivated H37Rv­immunized mice. Our data collectively indicate that exposure to the viable H37Ra strain induces a stronger macrophage response compared to exposure to the heat-inactivated H37Rv strain, which may be associated with the increased surface expression of CD40L in activated macrophages.