Hypozincemia in COVID-19 Patients Correlates With Stronger Antibody Response.

Zinc ion as an enzyme cofactor exhibits antiviral and anti-inflammatory activity during infection, but circulating zinc ion level during Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is unclear. This study aimed to evaluate serum zinc ion level in Coronavirus Disease 2019 (COVID-19) patients and healthy subjects, as well as its correlation with antibodies against SARS-CoV-2. 114 COVID-19 patients and 48 healthy subjects (38 healthy volunteers and 10 close contacts of patients with COVID-19) were included. Zinc ion concentration and levels of antibodies against SARS-CoV-2 Spike 1 + Spike 2 proteins, nucleocapsid protein, and receptor-binding domain in serum were measured. Results showed that the concentration of zinc ion in serum from COVID-19 patients [median: 6.4 nmol/mL (IQR 1.5 - 12.0 nmol/mL)] were significantly lower than that from the healthy subjects [median: 15.0 nmol/mL (IQR 11.9 - 18.8 nmol/mL)] (p < 0.001) and the difference remained significant after age stratification (p < 0.001) or when the patients were at the recovery stage (p < 0.001). Furthermore, COVID-19 patients with more severe hypozincemia showed higher levels of IgG against the receptor-binding domain of SARS-CoV-2 spike protein. Further studies to confirm the effect of zinc supplementation on improving the outcomes of COVID-19, including antibody response against SARS-CoV-2, are warranted.

Preoperative Vitamin D Concentration and Cardiac, Renal, and Infectious Morbidity after Noncardiac Surgery.

BACKGROUND: Low 25-hydroxyvitamin D is associated with cardiovascular, renal, and infectious risks. Postsurgical patients are susceptible to similar complications, but whether vitamin D deficiency contributes to postoperative complications remains unclear. We tested whether low preoperative vitamin D is associated with cardiovascular events within 30 days after noncardiac surgery. METHODS: We evaluated a subset of patients enrolled in the biobank substudy of the Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) study, who were at least 45 yr with at least an overnight hospitalization. Blood was collected preoperatively, and 25-hydroxyvitamin D was measured in stored samples. The primary outcome was the composite of cardiovascular events (death, myocardial injury, nonfatal cardiac arrest, stroke, congestive heart failure) within 30 postoperative days. Secondary outcomes were kidney injury and infectious complications. RESULTS: A total of 3,851 participants were eligible for analysis. Preoperative 25-hydroxyvitamin D concentration was 70 ± 30 nmol/l, and 62% of patients were vitamin D deficient. Overall, 26 (0.7%) patients died, 41 (1.1%) had congestive heart failure or nonfatal cardiac arrest, 540 (14%) had myocardial injury, and 15 (0.4%) had strokes. Preoperative vitamin D concentration was not associated with the primary outcome (average relative effect odds ratio [95% CI]: 0.93 [0.85, 1.01] per 10 nmol/l increase in preoperative vitamin D, P = 0.095). However, it was associated with postoperative infection (average relative effect odds ratio [95% CI]: 0.94 [0.90, 0.98] per 10 nmol/l increase in preoperative vitamin D, P adjusted value = 0.005) and kidney function (estimated mean change in postoperative estimated glomerular filtration rate [95% CI]: 0.29 [0.11, 0.48] ml min 1.73 m per 10 nmol/l increase in preoperative vitamin D, P adjusted value = 0.004). CONCLUSIONS: Preoperative vitamin D was not associated with a composite of postoperative 30-day cardiac outcomes. However, there was a significant association between vitamin D deficiency and a composite of infectious complications and decreased kidney function. While renal effects were not clinically meaningful, the effect of vitamin D supplementation on infectious complications requires further study.

Bufalin, a Traditional Chinese Medicine Compound, Prevents Tumor Formation in Two Murine Models of Colorectal Cancer.

Chemoprevention is cost-effective for colorectal cancer when targeted at intermediate- or high-risk populations. Bufalin is a cardiac glycoside extracted from the traditional Chinese medicine (TCM) "Chan Su," which has been used as an anticancer agent. On the basis of the relative safety of bufalin, we investigated whether bufalin could act as a chemoprophylactic agent to prevent colon tumorigenesis in two murine models, namely colitis-associated colorectal cancer and Apc germline mutation-developed colorectal cancer. Our results revealed that long-term (12-16 weeks) administration of low-dose bufalin (0.5 mg/kg) effectively suppressed tumorigenesis in both colorectal cancer models, accompanied by attenuated epithelial cell proliferation (reduced bromodeoxyuridine incorporation, lower levels of cyclin A, cyclin D1, cyclin E, and cyclin-dependent kinases-2/4, and higher levels of p21 and p27) and promoted apoptosis (increased TUNEL positivity and caspase-3/9 cleavages, reduced levels of Bcl-2, Bcl-xL and survivin, and increased levels of Bax and Bak). Bufalin also suppressed the expression of proinflammatory mediators [reduced levels of cyclooxygenase-2, tumor TNFα, IL1ß, IL6, C-X-C motif chemokine ligand (CXCL)-1, CXCL-2, and CXCL-5] in the colitis-associated colorectal cancer model. These effects were associated with the inhibition of oncogenic NF-κB and PI3K/Akt pathways. Our findings unveil a novel chemoprophylactic action of bufalin in colorectal cancer in vivo and provided efficacy data and mechanistic evidence for further clinical evaluation of this TCM compound for colorectal cancer chemoprevention in individuals at risk of colorectal cancer.

Yin Yang 1-mediated epigenetic silencing of tumour-suppressive microRNAs activates nuclear factor-κB in hepatocellular carcinoma.

Enhancer of zeste homolog 2 (EZH2) catalyses histone H3 lysine 27 trimethylation (H3K27me3) to silence tumour-suppressor genes in hepatocellular carcinoma (HCC) but the process of locus-specific recruitment remains elusive. Here we investigated the transcription factors involved and the molecular consequences in HCC development. The genome-wide distribution of H3K27me3 was determined by chromatin immunoprecipitation coupled with high-throughput sequencing or promoter array analyses in HCC cells from hepatitis B virus (HBV) X protein transgenic mouse and human cell models. Transcription factor binding site analysis was performed to identify EZH2-interacting transcription factors followed by functional characterization. Our cross-species integrative analysis revealed a crucial link between Yin Yang 1 (YY1) and EZH2-mediated H3K27me3 in HCC. Gene expression analysis of human HBV-associated HCC specimens demonstrated concordant overexpression of YY1 and EZH2, which correlated with poor survival of patients in advanced stages. The YY1 binding motif was significantly enriched in both in vivo and in vitro H3K27me3-occupied genes, including genes for 15 tumour-suppressive microRNAs. Knockdown of YY1 reduced not only global H3K27me3 levels, but also EZH2 and H3K27me3 promoter occupancy and DNA methylation, leading to the transcriptional up-regulation of microRNA-9 isoforms in HCC cells. Concurrent EZH2 knockdown and 5-aza-2'-deoxycytidine treatment synergistically increased the levels of microRNA-9, which reduced the expression and transcriptional activity of nuclear factor-κB (NF-κB). Functionally, YY1 promoted HCC tumourigenicity and inhibited apoptosis of HCC cells, at least partially through NF-κB activation. In conclusion, YY1 overexpression contributes to EZH2 recruitment for H3K27me3-mediated silencing of tumour-suppressive microRNAs, thereby activating NF-κB signalling in hepatocarcinogenesis.

Sensitivity of apoptosis-resistant colon cancer cells to tanshinones is mediated by autophagic cell death and p53-independent cytotoxicity.

BACKGROUND: Multidrug resistance (MDR) develops in nearly all patients with colon cancer. The reversal of MDR plays an important role in the success of colon cancer chemotherapy. One of the commonest mechanisms conferring MDR is the suppression of apoptosis in cancer cells. PURPOSE: This study investigated the sensitivity of cryptotanshinone (CTS) and dihydrotanshinone (DTS), two lipophilic tanshinones from a traditional Chinese medicine Salvia miltiorrhiza, in apoptosis-resistant colon cancer cells. METHODS: Cell viability was measured by MTT assay. Cell cycle distribution and apoptosis were determined by flow cytometry. Protein levels were analyzed by western blot analysis. The formation of acidic vesicular organelles was visualized by acridine orange staining. RESULTS: Experimental results showed that multidrug-resistant colon cancer cells SW620 Ad300 were sensitive to both CTS and DTS in terms of cell death, but with less induction of apoptosis when compared with the parental cells SW620, suggesting that other types of cell death such as autophagy could occur. Indeed, the two tanshinones induced more LC3B-II accumulation in SW620 Ad300 cells with increased autophagic flux. More importantly, cell viability was increased after autophagy inhibition, indicating that autophagy induced by the two tanshinones was pro-cell death. Besides, the cytotoxic actions of the two tanshinones were p53-independent, which could be useful in inhibiting the growth of apoptosis-resistant cancer cells with p53 defects. CONCLUSION: The current findings strongly indicate that both CTS and DTS could inhibit the growth of apoptosis-resistant colon cancer cells through induction of autophagic cell death and p53-independent cytotoxicity. They are promising candidates to be further developed as therapeutic agents in the adjuvant therapy for colon cancer, especially for the apoptosis-resistant cancer types.

Host immune defense peptide LL-37 activates caspase-independent apoptosis and suppresses colon cancer.

Cathelicidins are a family of bacteriocidal polypeptides secreted by macrophages and polymorphonuclear leukocytes (PMN). LL-37, the only human cathelicidin, has been implicated in tumorigenesis, but there has been limited investigation of its expression and function in cancer. Here, we report that LL-37 activates a p53-mediated, caspase-independent apoptotic cascade that contributes to suppression of colon cancer. LL-37 was expressed strongly in normal colon mucosa but downregulated in colon cancer tissues, where in both settings its expression correlated with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive apoptotic cells. Exposure of colon cancer cells to LL-37 induced phosphatidylserine externalization and DNA fragmentation in a manner independent of caspase activation. Apoptogenic function was mediated by nuclear translocation of the proapoptotic factors, apoptosis-inducing factor (AIF) and endonuclease G (EndoG), through p53-dependent upregulation of Bax and Bak and downregulation of Bcl-2 via a pertussis toxin-sensitive G-protein-coupled receptor (GPCR) pathway. Correspondingly, colonic mucosa of cathelicidin-deficient mice exhibited reduced expression of p53, Bax, and Bak and increased expression of Bcl-2 together with a lower basal level of apoptosis. Cathelicidin-deficient mice exhibited an increased susceptibility to azoxymethane-induced colon tumorigenesis, establishing pathophysiologic relevance in colon cancer. Collectively, our findings show that LL-37 activates a GPCR-p53-Bax/Bak/Bcl-2 signaling cascade that triggers AIF/EndoG-mediated apoptosis in colon cancer cells.

Triptolide inhibits colon cancer cell proliferation and induces cleavage and translocation of 14-3-3 epsilon.

Triptolide is a diterpenoid triepoxide derived from the traditional Chinese medical herb Tripterygium wilfordii. In the present study, we demonstrated that this phytochemical attenuated colon cancer growth in vitro and in vivo. Using a proteomic approach, we found that 14-3-3 epsilon, a cell cycle- and apoptosis-related protein, was altered in colon cancer cells treated with triptolide. In this regard, triptolide induced cleavage and perinuclear translocation of 14-3-3 epsilon. Taken together, our findings suggest that triptolide may merit investigation as a potential therapeutic agent for colon cancer, and its anticancer action may be associated with alteration of 14-3-3 epsilon.