Hepatitis B Virus Increases SphK1-S1P Synthesis by Promoting the Availability of the Transcription Factor USF1.

Hepatitis B virus (HBV) is the most common chronic viral infection globally, affecting ∼360 million people and causing about 1 million deaths annually due to end-stage liver disease or hepatocellular carcinoma. Current antiviral treatments rarely achieve a functional cure for chronic hepatitis B, highlighting the need for improved monitoring and intervention strategies. This study explores the role of the sphingosine kinase 1 (SphK1)-sphingosine-1-phosphate (S1P) axis in HBV-related liver injury. We investigated the association between serum S1P concentration and HBV DNA levels in chronic hepatitis B patients, finding a significant positive correlation. Additionally, SphK1 was elevated in liver tissues of HBV-positive hepatocellular carcinoma patients, particularly in HBsAg-positive regions. HBV infection models in HepG2-sodium taurocholate cotransporting polypeptide cells confirmed that HBV enhances SphK1 expression and S1P production. Inhibition of HBV replication through antiviral agents and the CRISPR-Cas9 system reduced SphK1 and S1P levels. Further, we identified the transcription factor USF1 as a key regulator of SphK1 expression during HBV infection. USF1 binds to the SphK1 promoter, increasing its transcriptional activity, and is upregulated in response to HBV infection. In vivo studies in mice demonstrated that HBV exposure promotes the expression of USF1 and SphK1-S1P. These findings suggest that the SphK1-S1P axis, regulated by HBV-induced USF1, could serve as a potential biomarker and therapeutic target for HBV-related liver injury.

Microascus cirrosus SZ 2021: A potentially new genotype of Microascus cirrosus, which can cause fatal pulmonary infection in patients with acute leukemia following haplo­HSCT.

Uncommon Microascus cirrosus (M. cirrosus) species have been reported to cause an increasing number of subcutaneous and invasive fungal infections worldwide; since the first human infection was reported in 1992, seven cases have been reported in PubMed. The present study reports a novel genotype named M. cirrosus SZ 2021 isolated from a patient undergoing hematopoietic stem cell transplantation, who exhibited extensive drug resistance and suffered a fatal pulmonary infection. This isolated M. cirrosus was cultured and determined by morphological observation, multi-locus sequence typing, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry, and whole genome sequencing by next-generation sequencing. The whole nucleotide sequence (32.61 Mb) has been uploaded in the NCBI database (PRJNA835605). In addition, M. cirrosus SZ 2021 was not sensitive to the commonly used antifungal drugs, including fluconazole, amphotericin B, 5-flucytosine and caspofungin. The current literature on human infections by M. cirrosus was reviewed to closely define the comprehensive clinical characteristics and etiological identification. In brief, the present study identified a new M. cirrosus and summarized the clinical characteristics of fungal pneumonia by M. cirrosus species. Complete laboratory identification methods from morphology to gene sequencing were also established for an improved etiological identification and further investigation into the real prevalence of invasive pneumonia by M. cirrosus.

Combining contrast-enhanced ultrasound and blood cell analysis to improve diagnostic accuracy of plasma cell mastitis.

Plasma cell mastitis is a benign suppurative disease of the breast, lack of specific clinical manifestations, which is easy to be misdiagnosed and mistreated, often confused with mastitis, breast cancer (BC), and other diseases. Thus, we aimed to establish a combined model of promoting diagnostic accuracy of plasma cell mastitis by contrast-enhanced ultrasound (CEUS) patterns and routine blood cell analysis. Eighty-eight plasma cell mastitis, 91 breast cancer, and 152 other benign breast diseases' patients grouped according to pathological diagnosis underwent CEUS and blood cell analysis examination; 100 healthy female donors were involved. All the plasma cell mastitis and breast cancer patients presented hyperenhancement of CEUS breast lesions compared with others. The majority of plasma cell mastitis (65/88) showed perfusion defect of CEUS patterns with smooth edge (56/65) and multiple lesions (49/65); in contrast, fewer breast cancer patients (30/91) displayed perfusion defect. White blood cell count (WBC), neutrophils, and neutrophils/lymphocytes ratio of blood cell analysis in plasma cell mastitis patients increased significantly compared with other patients (P < 0.0001). Combining perfusion defect of CEUS patterns and WBC yielded an area under the receiver operating characteristic curve of 0.831, higher than single 0.720 and 0.774, respectively. The cut-off value of WBC (7.28 × 109/L) helped remaining 65.2% (15/23) atypical cases to be correctly diagnosed as plasma cell mastitis, not misdiagnosed as breast cancer. In conclusion, CEUS presented a clear perfusion defect pattern of plasma cell mastitis lesion for the first time. A precise WBC by routine blood cell analysis test can assist CEUS examination in the differential diagnosis of plasma cell mastitis and breast cancer. It is a promised combination for laboratory diagnostic of PCM.

Flagellar Hook Protein FlgE Induces Microvascular Hyperpermeability via Ectopic ATP Synthase ß on Endothelial Surface.

We previously demonstrated the immunostimulatory efficacy of Pseudomonas aeruginosa flagellar hook protein FlgE on epithelial cells, presumably via ectopic ATP synthases or subunits ATP5B on cell membranes. Here, by using recombinant wild-type FlgE, mutant FlgE (FlgEM; bearing mutations on two postulated critical epitopes B and F), and a FlgE analog in pull-down assay, Western blotting, flow cytometry, and ELISA, actual bindings of FlgE proteins or epitope B/F peptides with ATP5B were all confirmed. Upon treatment with FlgE proteins, human umbilical vein endothelial cells (HUVECs) and SV40-immortalized murine vascular endothelial cells manifested decreased proliferation, migration, tube formation, and surface ATP production and increased apoptosis. FlgE proteins increased the permeability of HUVEC monolayers to soluble large molecules like dextran as well as to neutrophils. Immunofluorescence showed that FlgE induced clustering and conjugation of F-actin in HUVECs. In Balb/c-nude mice bearing transplanted solid tumors, FlgE proteins induced a microvascular hyperpermeability in pinna, lungs, tumor mass, and abdominal cavity. All effects observed in FlgE proteins were partially or completely impaired in FlgEM proteins or blocked by pretreatment with anti-ATP5B antibodies. Upon coculture of bacteria with HUVECs, FlgE was detectable in the membrane and cytosol of HUVECs. It was concluded that FlgE posed a pathogenic ligand of ectopic ATP5B that, upon FlgE-ATP5B coupling on endothelial cells, modulated properties and increased permeability of endothelial layers both in vitro and in vivo. The FlgE-ectopic ATP5B duo might contribute to the pathogenesis of disorders associated with bacterial infection or ectopic ATP5B-positive cells.

Advances in the role of m6A RNA modification in cancer metabolic reprogramming.

N6-methyladenosine (m6A) modification is the most common internal modification of eukaryotic mRNA and is widely involved in many cellular processes, such as RNA transcription, splicing, nuclear transport, degradation, and translation. m6A has been shown to plays important roles in the initiation and progression of various cancers. The altered metabolic programming of cancer cells promotes their cell-autonomous proliferation and survival, leading to an indispensable hallmark of cancers. Accumulating evidence has demonstrated that this epigenetic modification exerts extensive effects on the cancer metabolic network by either directly regulating the expression of metabolic genes or modulating metabolism-associated signaling pathways. In this review, we summarized the regulatory mechanisms and biological functions of m6A and its role in cancer metabolic reprogramming.

Radical-dominated reaction of CO-NO on a CaFe2O4 surface in sintering flue gas recirculation.

The catalytic reduction behaviours between NO and CO on a CaFe2O4 surface were studied using flue gas recirculation. The reaction mechanism and control principle were investigated via experiment and theoretical calculations. The experiment results show that CaFe2O4 can catalyse the reduction of NO by CO, and the NO conversion rate increases with the increase in CO concentration. The theoretical calculations indicate that the CO-NO reaction on CaFe2O4 surfaces complies with the Eley-Rideal mechanism, and the reaction path is controlled by nitrogen, oxygen and isocyanate radicals. Specifically, the dissociation of NO into nitrogen and oxygen radicals, and the formation of subsequent isocyanate radicals dominate the reaction. The results provide new insight into the intrinsic reaction mechanism and the meso-scale control principle, allowing us to propose a novel process design scheme to improve the NO x emission reduction efficiency in the flue gas recirculation process.

CP and CP-PGN protect mice against MRSA infection by inducing M1 macrophages.

Corynebacterium pyruviciproducens (C. pyruviciproducens, CP), as a newly discovered immunomodulator, has been confirmed to have a stronger immunoregulation than Propionibacterium acnes (P. acnes) of the traditional immune adjuvant, by previous experiments with model antigen ovalbumin and sheep red blood cells. Here, it was designed to assess its ability to resist methicillin-resistant Staphylococcus aureus (MRSA), since MRSA as a vital gram positive pathogen is characterized by high morbidity and mortality. In this report, it was indicated that C. pyruviciproducens and its peptidoglycan (CP-PGN) could help to be against bloodstream infection of MRSA with raised survival rate, decreased bacteria load and alleviated systemic inflammation, and these effects of CP-PGN were more pronounced. However, the whole CP was inclined to prevent localized abdominal infection of MRSA from progressing to a systemic infection. And they showed the potential as a therapeutic drug alone or combined with vancomycin. The diversity of capacity of activating macrophages induced by CP and CP-PGN may result in distinct resistance to MRSA in different infection models. Furthermore, both CP and CP-PGN induced M1 macrophages. In conclusion, CP and its PGN could act as promising immune agents to treat and prevent MRSA infection.

Expression and purification of the mGITR-Fc fusion protein and its effect on CD4⁺ T cells and dendritic cells in vitro.

Glucocorticoid­induced tumor necrosis factor receptor related protein (GITR) is a member of the tumor necrosis factor receptor superfamily. The present study attempted to obtain the mouse GITR­Fc fusion protein and investigate its function on the proliferation of CD4+ T cells and on the expression of mGITR ligand (mGITRL) on dendritic cells. The sequences of the mouse (m)GITR gene and mouse immunoglobulin G Fc (mIgGFc) were amplified from mouse spleen cells and introduced into a pET­32a(+) vector. Following the induction, purification and validation of the mGITR­Fc fusion protein, the mGITR­Fc fusion protein was used to analyze its function on the proliferation of CD4+ T cells and on the expression of mGITR on dendritic cells. A recombinant plasmid containing the mGITR gene fragment and mIgGFc was constructed, and the recombinant mGITR­Fc fusion protein was successfully expressed. The exogenous mGITR­Fc fusion protein inhibited the proliferation of CD4+ T cells, dependent on the presence of mGITRL. The exogenous mGITR­Fc fusion protein also inhibited the expression of mGITRL on the dendritic cells. In conclusion, the mGITR­Fc fusion protein was confirmed to exhibit biological functions of a co­stimulatory signal and reverse signal. These experiments provide the basis for further investigation of the function of the mGITR­Fc fusion protein on certain autoimmune diseases.

Corynebacterium pyruviciproducens, as an immune modulator, can promote the activity of macrophages and up-regulate antibody response to particulate antigen.

Corynebacterium pyruviciproducens is a newly discovered Corynebacterium species with no known pathogenic components such as diphtheria toxin and tuberculostearic acid, and it has similar biological properties to Propionibacterium acnes, but its role of immunoregulation is drawing people's attention. In this work, based on the role of macrophages in removal of pathogenic bacteria as a primary scavenger and particulate antigen-presenting cell, the stimulation of macrophages by C. pyruviciproducens was analyzed through detecting the levels of cytokine secretion and expression of membrane molecules, and the effect of C. pyruviciproducens in promoting antibody response to sheep red blood cells (SRBC) in vivo was detected. In vitro, C. pyruviciproducens led to a sharp release of interleukin-6 and tumour necrosis factor-α and encouraged the activation of macrophages including enhanced expressions of MHC-II, CD40, CD80 and CD86. In vivo, it enhanced the humoral immune response against SRBC, a particulate antigen. These observations suggest that C. pyruviciproducens, as an immunoregulator, can promote the host humoral immune response to pathogenic microorganisms by regulating macrophage function.

[Primary detection of biological functions of anti-hGITR(aa27-165);PcAb].

AIM: To detect the rabbit-derived polyclonal antibodies against extracellular protein segments of human glucocorticoid-inducible tumor necrosis factor receptors (anti-hGITR(aa27-165);PcAb) with regard to its capacity of linkage to natural GITR molecules and the function on CD4(+); T cells. METHODS: Human peripheral blood mononuclear cells (PBMCs) were isolated and cultured under stimulation; flow cytometry was applied to check the capacity of anti-hGITR(aa27-165);PcAb for linkage to natural GITR molecules on PBMCs; human CD4(+); T cells were isolated by immunological magnetic beads and (3);H-TdR incorporation tests were performed to observe improving-proliferation action of anti-hGITR(aa27-165);PcAb while CD4(+); T cells were cultured with or not with some cytokines. RESULTS: Anti-hGITR(aa27-165);PcAb was able to bind GITR molecules with natural conformation in a concentration-dependent way; furthermore, this PcAb could improve the reproduction of CD4(+); T cells. CONCLUSION: The rabbit-derived anti-hGITR(aa27-165);PcAb prepared in our laboratory is capable of linking to natural target molecules and possesses the activation function upon CD4(+); T cells, the further exploration should allow for its applications for diagnosis and treatment of relavent diseases.