Anti-Inflammatory Klotho Protein Serum Concentration Correlates with Interferon Gamma Expression Related to the Cellular Activity of Both NKT-like and T Cells in the Process of Human Aging

Serum α-Klotho with all-cause and cause-specific mortality

AIMS

The relationship between α-Klotho (αK) and mortality is controversial and has not been examined in a large, diverse cohort. We investigated the association between serum αK protein levels with all-cause and cause-specific mortality in a cohort representative of the US population.

METHODS

We used National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2016. A nonlinear association between mortality and αK levels as a quadratic variable were examined using Cox proportional hazard models and competing risk models. Multivariable models were adjusted for age, gender, race, hypertension, diabetes, smoking, alcohol use, physical activity, body mass index (BMI), serum cholesterol, estimated glomerular filtration rate, highest educational status attained and family income to poverty threshold ratio.

RESULTS

Of the 13 749 participants, 1569 (11%) died, 7092 (52%) were female, and 5918 (43%) were Caucasian. The mean (SD) of age was 58 (11) years, BMI 29.7 (6.7) kg/m2, and αK was 0.85 (0.31) ng/mL. In the adjusted Cox proportional hazards model with quadratic αK, we found a U-shaped relationship between all-cause mortality and αK levels (continuous αK hazard ratio [HR] = 0.56, 95% confidence interval [CI]: 0.37, 0.85; P = .007; squared-αK HR = 1.25, 95% CI: 1.11, 1.41; P < 0.001). A similar U-shaped relationship was noted between αK and cancer mortality in the adjusted Cox proportional hazards model (continuous αK HR = 0.45, 95% CI: 0.19, 1.06; P = 0.07; squared αK HR = 1.32, 95% CI: 1.07, 1.61; P = 0.009). No relationship was present with cardiovascular or other-cause mortality.

CONCLUSIONS

In this large diverse cohort, we report a U-shaped relationship between αK with all-cause and cancer mortality. Further research to elucidate the underlying biological mechanism of these relationships is needed.

Expression of a stress-inducible heme oxygenase-1 in NK cells is maintained in the process of human aging

Introduction

Heme oxygenase-1 (HO-1) is a stress-inducible heat shock protein (HSP32) that exerts cytoprotective effects against oxidative stress and inflammation, and is involved in the maintenance of cellular homeostasis. This study aimed to evaluate the expression of HO-1 in natural killer (NK) cells from individuals of different age groups after stimulation with various factors, and to analyze the relationships between the concentration of this cytoprotective protein and parameters corresponding to oxidative stress and inflammation, that is, NOD-like receptor protein 3 (NLRP3), glutathione (GSH), GSH disulfide (GSSG), and interleukin 6 (IL-6).

Methods

The study population comprised three age groups: young adults (age range, 19-23 years), older adults aged under 85 years (age range, 73-84 years), and older adults aged over 85 years (age range, 85-92 years). NLRP3, GSH, and GSSG concentrations were measured in serum, whereas the HO-1 concentration and IL-6 expression were studied in NK cells cultivated for 48 h and stimulated with IL-2, lipopolysaccharide (LPS), or phorbol 12-myristate 13-acetate (PMA) with ionomycin.

Results

The analysis of serum NLRP3, GSH, and GSSG concentrations revealed no statistically significant differences among the studied age groups. However, some typical trends of aging were observed, such as a decrease in GSH concentration and an increase in both GSSG level, and GSSG/GSH ratio. The highest basal expression of IL-6 and lowest basal content of HO-1 were found in NK cells of adults over 85 years of age. The NK cells in this age group also showed the highest sensitivity to stimulation with the applied factors. Moreover, statistically significant negative correlations were observed between HO-1 and IL-6 expression levels in the studied NK cells.

Conclusions

These results showed that NK cells can express HO-1 at a basal level, which was significantly increased in activated cells, even in the oldest group of adults. The reciprocal relationship between HO-1 and IL-6 expression suggests a negative feedback loop between these parameters.

Editorial for the Special Issue "Cytokines in Inflammatory Signaling"

The intricate interplay of cytokines within the inflammatory response serves as a cornerstone of both the maintenance of physiological homeostasis and the pathogenesis of proinflammatory diseases [...].

Interplay of Systemic Immune-Inflammation Index and Serum Klotho Levels: Unveiling a New Dimension in Rheumatoid Arthritis Pathology

Aim: The association between the systemic immune-inflammation index (SII) and serum Klotho concentrations (pg/ml) in patients with rheumatoid arthritis (RA) has not been elucidated. The purpose of this study was to clarify the relationship between the SII and serum Klotho concentrations in RA patients. Methods: All data come from the National Health and Nutrition Examination Survey (NHANES) database in the United States, which included 982 RA patients (age range: 40 to 79 years). The measurement data of the SII and serum Klotho are all from the NHANES mobile examination centre. We constructed a multivariate linear regression model to evaluate the association between the SII and serum Klotho levels in RA patients and conducted a subgroup analysis to test the stability of the statistical results. Results: Multivariate linear regression results indicated a negative linear relationship between the SII and serum Klotho concentrations in RA patients (β = -6.33, 95% CI [confidence interval]: -10.15 to -2.53). Compared to the quartile 1 group, the quartile 4 group was associated with significantly lower (P<0.001) serum Klotho concentrations (β = -120.93, 95% CI: -174.84 to -67.02). Compared with the quartile 1 group, with the increase in the SII, the β value showed a decreasing trend (P trend < 0.001). The subgroup analysis showed that none of the covariates affected the stability of these results (all P for interaction ≥ 0.05). Conclusion: There is a significant negative linear association between the SII and serum Klotho concentrations in RA patients. The SII can serve as a predictive indicator of serum Klotho concentrations in RA patients, and Klotho may be a potential anti-inflammatory target for RA treatment.