14-3-3ζ-Mediated Stimulation of Oxidative Phosphorylation Exacerbates Oxidative Damage Under Hypothermic Oxygenated Conditions in Human Renal Tubular Cells (HK-2)

Combination of Cold Storage in a Heavy Water-Containing Solution and Post-Reperfusion Hydrogen Gas Treatment Reduces Ischemia-Reperfusion Injury in Rat Livers

We previously reported the efficacy of cold storage (CS) using a heavy water-containing solution (Dsol) and post-reperfusion hydrogen gas treatment separately. This study aimed to clarify the combined effects of these treatments. Rat livers were subjected to 48-hour CS and a subsequent 90-minute reperfusion in an isolated perfused rat liver system. The experimental groups were the immediately reperfused control group (CT), the CS with University of Wisconsin solution (UW) group, the CS with Dsol group, the CS with UW and post-reperfusion H₂ treatment group (UW-H₂), and the CS with Dsol and post-reperfusion H₂ group (Dsol-H₂). We first compared the Dsol-H₂, UW, and CT groups to evaluate this alternative method to conventional CS. The protective potential of the Dsol-H₂ group was superior to that of the UW group, as evidenced by lower portal venous resistance and lactate dehydrogenase leakage, a higher oxygen consumption rate, and increased bile production. Multiple comparison tests among the UW, Dsol, UW-H₂, and Dsol-H₂ groups revealed that both treatments, during CS and after reperfusion, conferred a similar extent of protection and showed additive effects in combination therapy. Furthermore, the variance in all treatment groups appeared smaller than that in the no-treatment or no-stress groups, with excellent reproducibility. In conclusion, combination therapy with Dsol during CS and hydrogen gas after reperfusion additively protects against graft injury.

Serum Anti-14-3-3 Zeta Autoantibody as a Biomarker for Predicting Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is a common malignancy worldwide. Alpha-fetoprotein (AFP) is still the only serum biomarker widely used in clinical settings. However, approximately 40% of HCC patients exhibit normal AFP levels, including very early HCC and AFP-negative HCC; for these patients, serum AFP is not applicable as a biomarker of early detection. Thus, there is an urgent need to identify novel biomarkers for patients for whom disease cannot be diagnosed early. In this study, we screened and identified novel proteins in AFP-negative HCC and evaluated the feasibility of using autoantibodies to those protein to predict hepatocarcinogenesis. First, we screened and identified differentially expressed proteins between AFP-negative HCC tissue and adjacent non-tumor liver tissue using SWATH-MS proteome technology. In total, 2,506 proteins were identified with a global false discovery rate of 1%, of which 592 proteins were expressed differentially with 175 upregulated and 417 downregulated (adjusted p-value <0.05, fold-change FC ≥1.5 or ≤0.67) between the tumor and matched benign samples, including 14-3-3 zeta protein. For further serological verification, autoantibodies against 14-3-3 zeta in serum were evaluated using enzyme-linked immunosorbent, Western blotting, and indirect immunofluorescence assays. Five serial serum samples from one patient with AFP-negative HCC showed anti-14-3-3 zeta autoantibody in sera 9 months before the diagnosis of HCC, which gradually increased with an increase in the size of the nodule. Based on these findings, we detected the prevalence of serum anti-14-3-3 zeta autoantibody in liver cirrhosis (LC) patients, which is commonly considered a premalignant liver disease of HCC. We found that the prevalence of autoantibodies against 14-3-3 zeta protein was 16.1% (15/93) in LC patient sera, which was significantly higher than that in patients with chronic hepatitis (0/75, p = 0.000) and normal human sera (1/60, 1.7%, p = 0.01). Therefore, we suggest that anti-14-3-3 zeta autoantibody might be a biomarker for predicting hepatocarcinogenesis. Further follow-up and research of patients with positive autoantibodies will be continued to confirm the relationship between anti-14-3-3 zeta autoantibody and hepatocarcinogenesis.

Sodium fluoride causes oxidative damage to silkworm (Bombyx mori) testis by affecting the oxidative phosphorylation pathway

Bombyx mori was used to study the molecular mechanism of fluoride induced reproductive toxicity. In our previous study, we confirmed the physiological and biochemical effects of NaF on reproductive toxicity, and we found that the molecular mechanism of NaF induced reproductive damage may be associated with the oxidative phosphorylation pathway. To further study the function of NaF exposure on the oxidative phosphorylation pathway in the testis in Bombyx mori, and the relationship between oxidative phosphorylation and oxidative stress, we measured the changes in the main ROS (O2- and H2O2) in the testis, the activity of the main electron transport chain complex enzymes in the oxidative phosphorylation pathway and the transcription levels of the corresponding genes; we additionally performed pathological observations of the silkworm testis after exposure to 200 mg/L NaF solution for different times. The content of O2- and H2O in the silkworm gonads increased significantly at 24 h, 72 h and 120 h after NaF stress. The activity of mitochondrial complexes I, III, IV and V in the silkworm testis was significantly greater than that in the control group. RT-PCR analysis suggested that the mRNA transcription levels of NADH-CoQ1, Cyt c reductase, Cyt c oxidase and ATP synthase genes were up-regulated significantly. Histopathological investigation showed that the damage to the silkworm testis was more severe with increasing NaF exposure times. These results indicated that NaF stress affects the NADH respiratory chain of the mitochondrial electron transport chain and increases the activity of related enzyme complexes, thus destroying the balance of the electron transport chain. Subsequently, the content of ROS in cells significantly increases, thus resulting in oxidative stress reactions in cells. These results enable better understanding of the testis-damaging molecular toxicological mechanism of NaF.

The Phenolic Antioxidant 3,5-dihydroxy-4-methoxybenzyl Alcohol (DHMBA) Prevents Enterocyte Cell Death under Oxygen-Dissolving Cold Conditions through Polyphyletic Antioxidant Actions

Cold preservation in University of Wisconsin (UW) solution is not enough to maintain the viability of the small intestine, due to the oxidative stress. The novel phenolic antioxidant 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA) has dual properties to reduce oxidative stress, radical scavenging, and antioxidant protein induction, in other cells. This study was designed to determine whether DHMBA reduces cold preservation injury of enterocytes, and to identify the effector site. Enterocytes were subjected to 48-h cold preservation under atmosphere in UW solution (±DHMBA), and then returned to normal culture to replicate reperfusion of the small intestine after cold preservation. At the end of cold preservation (ECP) and at 1, 3, 6, and 72 h after rewarming (R1h, R3h, R6h, and R72h), we evaluated cell function and the injury mechanism. The results showed that DHMBA protected mitochondrial function mainly during cold preservation, and suppressed cell death after rewarming, as shown by the MTT, ATP, mitochondrial membrane potential, LDH, and lipid peroxidation assays, together with enhanced survival signals (PI3K, Akt, p70S6K) and induction of antioxidant proteins (HO-1, NQO-1, TRX-1). We found that DHMBA mitigates the cold-induced injury of enterocytes by protecting the mitochondria through direct and indirect antioxidative activities.

A pan-cancer analysis of molecular characteristics and oncogenic role of hexokinase family genes in human tumors

Hexokinase (HK) plays a key role in various biological processes such as glycolysis of tumor cells. However, there is still a lack of systematic understanding of the contribution of HK family genes in different types of cancer. In the present study, we systematically analyzed the molecular changes and clinical correlations of HK family genes in 33 types of cancer extracted from more than 10,000 subjects. As a result, there were extensive genetic changes in HK family genes and the expression levels of HK family were significantly correlated with the activity of cancer marker-related pathways. In addition, HK family genes may be useful in predicting prognosis and therapeutic efficacy. Moreover, HK1,HK2 and HK3 may become potential oncogenes across a variety of cancer types. Furthermore, the oncogenic functions of HK1 in bladder cancer have been confirmed in vitro. Collectively, our results provide valuable resources to guide the mechanism and therapeutic analysis concerning the role of HK family genes in cancer.

Tumor-associated autoantibodies are useful biomarkers in immunodiagnosis of α-fetoprotein-negative hepatocellular carcinoma

AIM

To determine the prevalence and diagnostic value of autoantibodies in α-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC).

METHODS

Fifty-six serum samples from AFP-negative HCC cases, 86 from AFP-positive HCC cases, 168 from chronic liver disease cases, and 59 from normal human controls were included in this study. Autoantibodies to nucleophosmin (NPM)1, 14-3-3zeta and mouse double minute 2 homolog (MDM2) proteins in AFP-negative HCC serum were evaluated by enzyme-linked immunosorbent assay. Partially positive sera were further evaluated by western blotting. Immunohistochemistry was used to detect the expression of three tumor-associated antigens (TAAs) in AFP-negative HCC and normal control tissues.

RESULTS

The frequency of autoantibodies to the three TAAs in AFP-negative HCC sera was 21.4%, 19.6% and 19.6%, which was significantly higher than in the chronic liver disease cases and normal human controls (P < 0.01) as well as AFP-positive HCC cases. The sensitivity of the three autoantibodies for diagnosis of AFP-negative HCC ranged from 19.6% to 21.4%, and the specificity was approximately 95%. When the three autoantibodies were combined, the sensitivity reached 30.4% and the specificity reached 91.6%.

CONCLUSION

Autoantibodies to NPM1, 14-3-3zeta and MDM2 may be useful biomarkers for immunodiagnosis of AFP-negative HCC.