Effects of urban particulate matter on the quality of erythrocytes.

With the acceleration of industrialisation and urbanisation, air pollution has become a serious global concern as a hazard to human health, with urban particulate matter (UPM) accounting for the largest share. UPM can rapidly pass into and persist within systemic circulation. However, few studies exist on whether UPM may have any impact on blood components. In this study, UPM standards (SRM1648a) were used to assess the influence of UPM on erythrocyte quality in terms of oxidative and metabolic damage as well as phagocytosis by macrophages in vitro and clearance in vivo. Our results showed that UPM had weak haemolytic properties. It can oxidise haemoglobin and influence the oxygen-carrying function, redox balance, and metabolism of erythrocytes. UPM increases the content of reactive oxygen species (ROS) and decreases antioxidant function according to the data of malonaldehyde (MDA), glutathione (GSH), and glucose 6 phosphate dehydrogenase (G6PDH). UPM can adhere to or be internalised by erythrocytes at higher concentrations, which can alter their morphology. Superoxide radicals produced in the co-incubation system further disrupted the structure of red blood cell membranes, thereby lowering the resistance to the hypotonic solution, as reflected by the osmotic fragility test. Moreover, UPM leads to an increase in phosphatidylserine exposure in erythrocytes and subsequent clearance by the mononuclear phagocytic system in vivo. Altogether, this study suggests that the primary function of erythrocytes may be affected by UPM, providing a warning for erythrocyte quality in severely polluted areas. For critically ill patients, transfusion of erythrocytes with lesions in morphology and function will have serious clinical consequences, suggesting that potential risks should be considered during blood donation screening. The current work expands the scope of blood safety studies.

19q13.12 KRAB zinc-finger protein ZNF383 represses p53 signaling pathway by interacting with p53.

As one of the most important tumor suppressors, the activity of p53 is precisely regulated. However, the mechanism of p53 regulation is still being elucidated and new regulatory molecules for p53 have also been frequently identified. Our previous works revealed that two members of the KRAB zinc-finger protein (KZFP) family Apak and PISA, which are located on human 19q13.12, participated in the regulation of p53 signaling pathway. KZFPs genes are mainly amplified via tandem in situ duplication during evolution, which indicates that similar sequences and functions may be conserved in evolutionarily and physically close KZFPs. Here, we revealed that ZNF383, another member of the KZFPs mapped at 19q13.12, could inhibit p53-mediated apoptosis and the activation of IFN-ß pathway by decreasing the H3K36me2 level at p53's binding sites and the attenuating the binding of p53 to its target genes. We further explored the effect of other KZFPs clustered on 19q13.12 on p53, and found that 85% of these KZFPs exerted p53-repressive activity. Intriguingly, an acidic amino acid-enriched sequence, the SAcL motif in the zinc-finger domains of these KZFPs, was found to be critical for p53 binding. Taken together, our findings revealed the KZFPs cluster located at 19q13.12 not only was involved in p53 regulation but also exhibited different features in the selective regulation of p53 and functional mechanisms, and for the first time, confirmed a motif in KZFPs that mediates the interaction of KZFPs and p53. These results would enrich the knowledge on the role, sequence features, and functional mechanisms of the KZFP family in p53 regulation.

Cadmium mediates pyroptosis of human dermal lymphatic endothelial cells in a NLRP3 inflammasome-dependent manner.

Pyroptosis is a form of inflammasome-trigged programmed cell death in response to a variety of stimulators, including environmental cytotoxic pollutant Cadmium (Cd). Vascular endothelial cell is one of the first-line cell types of Cd cell toxicity. Studies report that Cd exposure causes pyroptosis in vascular endothelial cells. Vascular and lymphatic endothelial cells have many common properties, but these two cell types are distinguished in gene expression profile and the responsive behaviors to chemokine or physical stimulations. Whether Cd exposure also causes pyroptosis in lymphatic endothelial cells has not been investigated. Here, we found that Cd treatment significantly decreased the viability of human dermal lymphatic endothelial cells (HDLECs). Cd treatment induced inflammasome activation indicated by elevated cleavage of pro-caspase-1 into active form Casp1p20, elevated secretion of pro-inflammatory cytokines and production of reactive oxygen species (ROS). Flow cytometry showed that caspase-1 activity was significantly increased in Cd-treated cells. Moreover, knockdown of NLRP3 effectively rescued Cd-induced inflammasome activation and pyroptosis in HDLECs. Collectively, our results indicated that Cd induced pyroptosis in a NLRP3 inflammasome-dependent manner in lymphatic endothelial cells.

Current advances in nanomaterials affecting morphology, structure, and function of erythrocytes.

In recent decades, nanomaterials have been widely used in the field of biomedicine due to their unique physical and chemical properties, and have shown good prospects for in vitro diagnosis, drug delivery, and imaging. With regard to transporting nanoparticles (NPs) to target tissues or organs in the body intravenously or otherwise, blood is the first tissue that NPs come into contact with and is also considered an important gateway for targeted transport. Erythrocytes are the most numerous cells in the blood, but previous studies based on interactions between erythrocytes and NPs mostly focused on the use of erythrocytes as drug carriers for nanomedicine which were chemically bound or physically adsorbed by NPs, so little is known about the effects of nanoparticles on the morphology, structure, function, and circulation time of erythrocytes in the body. Herein, this review focuses on the mechanisms by which nanoparticles affect the structure and function of erythrocyte membranes, involving the hemocompatibility of NPs, the way that NPs interact with erythrocyte membranes, effects of NPs on erythrocyte surface membrane proteins and their structural morphology and the effect of NPs on erythrocyte lifespan and function. The detailed analysis in this review is expected to shed light on the more advanced biocompatibility of nanomaterials and pave the way for the development of new nanodrugs.

Increased interleukin-32, interleukin-1, and interferon-γ levels in serum from hepatitis B patients and in HBV-stimulated peripheral blood mononuclear cells from healthy volunteers.

BACKGROUND: Few studies showed the changes in cytokine profiles after infection by hepatitis B virus (HBV), the most common viral liver disease worldwide. This study examined the relationship between interleukin (IL)-32, IL-1, and interferon (IFN)-γ levels and HBV load. METHODS: IL-32, IL-1, and IFN-γ levels in hepatitis B patients serum and HBV-stimulated PBMCs were measured by ELISA. Gene transcripts in PBMCs from hepatitis B patients and HBV-stimulated PBMCs from healthy controls were measured by real-time PCR. RESULTS: IL-32, IL-1, and IFN-γ protein levels in serum from hepatitis B patients were significantly higher than those in healthy volunteers (P<0.05). Hepatitis B patients showed significantly higher expression of IL-32, IL-1, and IFN-γ transcripts than healthy volunteers (P<0.05). IL-32, IL-1, and IFN-γ levels in PBMCs stimulated by different amounts of HBV were significantly higher than those in HBV-unstimulated PBMCs (P<0.05). Real-time PCR results were consistent with the ELISA results. CONCLUSIONS: The levels of IL-32, IL-1, and IFN-γ protein and transcripts in serum and PBMCs from hepatitis B patients were higher than those in healthy volunteers. Similarly, both were higher in PBMCs from healthy volunteers stimulated by HBV in vitro. However, the changes in cytokine levels were not proportional to the viral load.

LncRNA PVT1 regulates growth, migration, and invasion of bladder cancer by miR-31/ CDK1.

PURPOSE: The aim of our study was to validate the sway of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) on the metabolism and growth of bladder cancer cells by microRNA-31 (miR-31)/cyclin-dependent kinase 1 ( CDK1). METHODS: The Gene Expression Omnibus database was used for analyzing the differentially expressed lncRNA and messenger RNA (mRNA) in bladder cancer tissues, with the highly expressed lncRNA PVT1 and mRNA CDK1 screened out. The expression level of PVT1 was detected by quantitative reverse-transcription polymerase chain reaction, cell viability by Cell Counting Kit-8 assay, cell proliferation and scratch by 5-bromo-2'-deoxyuridine assay, cell migration and invasion by transwell assays, the expression level of CDK1 by immunohistochemistry and western blot analysis, transcription factor targeting by dual-luciferase assay, and the effect of PVT1 on bladder cancer growth by nude mice tumor formation experiment. RESULTS: LncRNA PVT1 and mRNA CDK1 had a higher expression in bladder cancer cells than that in neighboring tissues. Activity, proliferation, colony formation, migration, and invasion of bladder cancer cell were noticeably reduced by the PVT1 inhibitor than that of control group. PVT1 and CDK1 have binding sites with miR-31. When miR-31 decreased, CDK1 mRNA and protein levels increased in vivo experiments in nude mice. When PVT1 was downregulated, the tumor size was significantly reduced and tumor proliferation was curbed. Immunohistochemistry showed that the positive rate of CDK1 and Ki-67 decreased and the expression of miR-31 increased after PVT1 was inhibited. CONCLUSIONS: LncRNA PVT1 was overexpressed in bladder cancer cells, and it was downregulated miR-31 to enhance CDK1 expression and facilitate bladder cancer cells proliferation, migration, and invasion.

Influence of miR-520e-mediated MAPK signalling pathway on HBV replication and regulation of hepatocellular carcinoma cells via targeting EphA2.

We determined the role of miR-520e in the replication of hepatitis B virus (HBV) and the growth of hepatocellular carcinoma (HCC) cells. MiR-520e and EPH receptor A2 (EphA2) in HBV-positive HCC tissues and cells were detected, and we studied the impact of miR-520e and the EphA2 receptor in cellular and murine HBV replication models. We find that MiR-520e was upregulated and EphA2 was downregulated in HBV-positive HCC tissues and cells. MiR-520e was decreased in Huh7-X and HepG2-X cells in which HBx was stably expressed, but was dose-dependently elevated after interfering with HBx. Additionally, miR-520e mimic and si-EphA2 groups were reduced in association with increases in HBV DNA content, HBsAg and HBeAg levels, cell proliferation and were enhanced in the expressions of EphA2, p-p38MAPK/p38MAPK, phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2)/ERK1/2 and cell apoptosis. Furthermore, si-EphA2 reversed the promotion effect of miR-520e inhibitor on HBV replication and tumour cell growth. Upregulating miR-520e in rAAV8-1.3HBV-infected mouse resulted in reduced EphA2 in liver tissues and HBV DNA content in serum. We find that MiR-520e was decreased in HBV-positive HCC, while overexpression of miR-520e blocked p38MAPK and ERK1/2 signalling pathways by an inhibitory effect on EphA2 and ultimately reduced HBV replication and inhibited tumour cell growth. These data indicate a role for miR-520e in the regulation of HBV replication.

[Cloning and expression of human interleukin-32 and studies on its bioactivity].

AIM: To clone human interleukin-32(hIL-32) gene and express it in E.coli efficiently. METHODS: The gene of hIL-32 was amplified by RT-PCR from human peripheral blood mononuclear cells (PBMC) which stimulated with Con A for 60 h. The PCR product was inserted into the pMD18-T vector. The hIL-32 cDNA confirmed by sequencing was inserted into expression vector pET-30a(+) and expressed in E.coli BL21(DE3) strain. The hIL-32 protein expression was induced by IPTG and assayed by SDS-PAGE and coomassie blue stain. The recombination protein was identified by Western blot and its biological activity was analyzed. RESULTS: DNA sequencing confirmed that the cloned cDNA was identical to the published sequence of hIL-32 that the nucleotide sequence of this gene was 567 bp. The recombinant plasmid pET30a-hIL32 was transformed into E.coli BL21(DE3) strain for expression. An expected 28 kDa protein of hIL-32 was found mainly in the induced host strains by SDS-PAGE and coomassie blue stain. The 28 kDa protein was recognized by anti-IL-32 antibody in western blot. The purified recombination protein could induce the producing of IL-6 in the human PBMC. CONCLUSION: We have successfully cloned the gene and expressed the protein of hIL-32 and the expressed protein has specific bioactivity.

Effects of reticuloendotheliosis virus and Marek's disease virus infection and co-infection on IFN-gamma production in SPF chickens.

Two experiments were used to examine the potential role of IFN-gamma in chickens infected with reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). First, chickens were infected with REV and/or MDV at 5 days of age and examined from 3 to 50 days post-infection (dpi). In REV+MDV co-infection chickens, IFN-gamma ELISA demonstrated a 3-fold increase at 7 dpi compared to the controls, while REV alone caused a 5-fold increase, the IFN-gamma levels peaked, and then gradually decreased. IFN-gamma levels significantly decreased in MDV infection at 3 dpi and 15 dpi. Second, experiments were designed to determine the effects of different viruses and ConA on IFN-gamma production. For REV- or MDV-infected chickens, the IFN-gamma levels decreased slightly after adding ConA. This is the first report of IFN-gamma production in SPF chickens infected with REV and MDV measured by directly quantitative method.