DataSheet_1_The causal association between circulating cytokines with the risk of frailty and sarcopenia under the perspective of geroscience.zip

IntroductionCirculating cytokines were considered to play a critical role in the initiation and propagation of sarcopenia and frailty from observational studies. This study aimed to find the casual association between circulating cytokines and sarcopenia and frailty from a genetic perspective by two-sample Mendelian randomization (MR) analysis.MethodsData for 41 circulating cytokines were extracted from the genome-wide association study dataset of 8,293 European participants. Inverse-variance weighted (IVW) method, MR-Egger, and weighted median method were applied to assess the relationship of circulating cytokines with the risk of aging-related syndromes and frailty. Furthermore, MR-Egger regression was used to indicate the directional pleiotropy, and Cochran’s Q test was used to verify the potential heterogeneity. The “leave-one-out” method was applied to visualize whether there was a causal relationship affected by only one anomalous single-nucleotide polymorphisms.ResultsGenetic predisposition to increasing levels of interleukin-10 (IL-10), IL-12, and vascular endothelial growth factor (VEGF) was associated with the higher risk of low hand grip strength according to the IVW method [R = 1.05, 95% CI = 1.01–1.10, P = 0.028, false discovery rate (FDR)–adjusted P = 1.000; OR = 1.03, 95% CI = 1.00–1.07, P = 0.042, FDR-adjusted P = 0.784; OR = 1.02, 95% CI = 1.00–1.05, P = 0.038, FDR-adjusted P = 0.567]. Furthermore, genetically determined higher macrophage colony-stimulating factors (M-CSFs) were associated with a lower presence of appendicular lean mass (OR = 1.01, 95% CI = 1.00–1.02, P = 0.003, FDR-adjusted P = 0.103). Monokine induced by interferon-γ (MIG) and tumor necrosis factor–beta (TNF-β) were associated with a higher risk of frailty (OR = 1.03, 95% CI = 1.01–1.05, P ConclusionGenetic predisposition to assess IL-10, IL-12, and VEGF levels was associated with a higher risk of low hand grip strength and M-CSF with the presence of appendicular lean mass. The high levels of TNF-β and MIG were associated with a higher risk of frailty. More studies will be required to explore the molecular biological mechanisms underlying the action of inflammatory factors.</p

Effect of carnosine on mitochondria membrane potentials of spleen lymphocytes in restraint-stressed mice.

<p>Spleen lymphocyte samples containing 5×10⁵ cells were stained with rhodamine-123. After incubation and wash, cells were resuspended in PBS. <i>ΔΨm</i> was determined using a flow cytometer. Data represented mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal group is at ^##p<0.01, and from model group at ^*p<0.05, ^**p<0.01.</p

<i>In vitro</i> effect of carnosine on the number of spleen lymphocytes (including NK cells) treated with corticosterone.

<p>Carnosine had no tendency to inhibit the reduction of total lymphocytes (A) and NK cells (B) induced by corticosterone <i>in vitro</i>. Data represented mean ± S.E.M. of triplicate assays. The significance of differences from untreated cells is at ^##p<0.01.</p

<i>In vivo</i> and <i>in vitro</i> effects of carnosine on the proliferative response (stimulation index) of spleen lymphocytes stimulated by ConA.

<p>(A) Carnosine increased ConA-stimulated lymphocyte proliferation <i>in vivo</i>. Data represented mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal is at ^##p<0.01, and from model at ^*p<0.05, ^**p<0.01. (B) Carnosine increased ConA-stimulated lymphocyte proliferation by treatment <i>in vitro</i>. Data represented mean ± S.E.M. of triplicate assays. The significance of differences from normal is at ^##p<0.01, and from model at ^*p<0.05, ^**p<0.01.</p

Effects of carnosine on brain histamine concentration (pmol/g tissue) in restraint-stressed mice.

<p>Brain regions including cerebral cortex, hippocampus and hypothalamus were rapidly dissected and homogenized in PBS containing 3% perchloric acid. Histamine level in brain regions was determined by HPLC-ECD. The results represent mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal group was at</p>##<p>p<0.01, and model group at</p>**<p>p<0.01, as determined by ANOVA analysis.</p

Effect of carnosine on gene expressions of GR, Bax and Bcl-2 mRNAs in spleen lymphocytes of restraint-stressed mice.

<p>RT-PCR was employed to determine the effect of carnosine on the expression of GR, Bax and Bcl-2 mRNAs. Relative expression values for each target gene were expressed as a ratio of target gene expression level to 18S expression level. Data represented mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal is at ^##p<0.01, and from model at ^*p<0.05, ^**p<0.01.</p

Effects of carnosine on NK cell number and cytotoxic activity in spleen lymphocytes of restraint-stressed mice.

<p>Spleen lymphocyte samples containing 1×10⁶ cells were stained with anti-CD3 (FITC)/anti-NK1.1 (PE) antibody to assess the percentage of NK cells (NK⁺CD3⁻) by flow cytometry. NK cell number was calculated according to NK cell percentage and total spleen lymphocyte number. In the determination of NK cell cytotoxic activity, target cells were YAC-1 cells. YAC-1 cells, stained with DiO, were mixed with freshly isolated spleen lymphocytes and incubated. Then PI was added to the mixtures. After incubation, NK cell activity was determined by flow cytometry. The results represent mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal group was at</p>##<p>p<0.01, and model group at</p>*<p>p<0.05,</p>**<p>p<0.01, as determined by ANOVA analysis.</p

Effect of carnosine on lymphocyte apoptosis confirmed by TUNEL assay.

<p>(A) The TUNEL assay was carried out by One Step TUNEL Apoptosis Assay Kit. The images of TUNEL positive cells were captured by a fluorescence microscope (200×). (B) Quantitative result of TUNEL assay was analyzed. Data represented mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal is at ^##p<0.01, and from model at ^**p<0.01.</p

Effect of carnosine on cytochrome c (Cyt c) contents in mitochondria and cytoplasm in restraint-stressed mice.

<p>Spleen lymphocytes samples containing (2×10⁶) were gently lysed with lysis buffer. Lysates were centrifuged to obtain supernatants (cytosolic extracts free of mitochondria) and the pellets (fraction that contains mitochondria). These two fractions were adjusted to 2 mg protein/ml in the buffer. Contents of cytochrome c were determined using difference spectra at the wavelength pairs of 550∼535, 554∼540 and 563∼577 respectively. The results represent mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal group is at</p>##<p>p<0.01, and from model group at</p>*<p>p<0.05,</p>**<p>p<0.01, as determined by ANOVA analysis.</p

Effect of carnosine on plasma corticosterone level of restraint-stressed mice.

<p>Blood containing heparin was centrifuged to obtain plasma. Corticosterone was extracted from plasma by acetic ether, and its content was determined by HPLC with a UV detector at 254 nm. Data represented mean ± S.E.M. obtained from 10 animals in each group. The significance of differences from normal group is at ^##p<0.01, and from model group at ^**p<0.01.</p