Inhibition of hexokinase 2 with 3-BrPA promotes MDSCs differentiation and immunosuppressive function.

The adoptive transfer of ex vivo generated myeloid-derived suppressor cells (MDSCs) may be a promising therapeutic strategy for preventing allograft rejection after solid organ transplantation. Currently, the precise role of immune-metabolic pathways in the differentiation and function of MDSCs is not fully understood. Hexokinase 2 (HK2) is an isoform of hexokinase and is a key enzyme involved in the increased aerobic glycolysis of different immune cells during their activation and function. Here, we demonstrate that the addition of HK2 inhibitor 3-Bromopyruvic acid (3-BrPA) into traditional MDSCs induction system in vitro significantly promoted MDSCs production and enhanced their immunosuppressive function. Treatment with 3-BrPA increased the expression of MDSC-related immunosuppressive molecules, such as iNOS, Arg1, and CXCR2. Moreover, the adoptive transfer of 3-BrPA-treated MDSCs significantly prolonged the survival time of mouse heart allografts. This study provides a novel strategy to solve the problems of harvesting enough autologous cells for MDSC production from sick patients, and producing functionally enhanced MDSCs for preventing graft rejection and inducing tolerance.

Corrigendum: The m6A-methylated mRNA pattern and the activation of the Wnt signaling pathway under the hyper-m6A-modifying condition in the keloid.

[This corrects the article DOI: 10.3389/fcell.2022.947337.].

Novel IKZF3 transcriptomic signature correlates with positive outcomes of skin cutaneous melanoma: A pan-cancer analysis.

To investigate the potential relationship between Ikaros family genes and skin cutaneous melanoma (SKCM), we undertook a pan-cancer analysis of the transcriptional signature and clinical data of melanoma through multiple databases. First, 10,327 transcriptomic samples from different cancers were included to determine the overall characteristics and clinical prognoses associated with Ikaros gene expression across cancer types. Second, differentially expressed genes analysis, prognostic evaluation, and gene set enrichment analysis were employed to investigate the role of Ikaros (IKZF) genes in SKCM. Third, we evaluated the relationship between Ikaros family genes and SKCM immune infiltrates and verified the findings using the GEO single-cell sequencing dataset. The results show that Ikaros genes were widely expressed among different cancer types with independently similar patterns as follows: 1. IKZF1 and IKZF3, and 2. IKZF2 and IKZF4-5. IKZF2 and IKZF5 were downregulated in the primary tumor, and IKZF1-3 expression decreased significantly as the T-stage or metastasis increased in SKCM. Moreover, high IKZF1-3 expression was associated with better overall survival, disease-specific survival, and progression-free interval. IKZF3 is an independent prognostic factor of SKCM. Among Ikaros genes, the expression of IKZF1 and IKZF3 positively correlated with the infiltration level of CD4+ T cells and CD8+ T cells, B cells, and Tregs in SKCM and negatively correlated with the infiltration level of M0 and M1 macrophages. Moreover, single-cell sequencing data analysis revealed that IKZF1 and IKZF3 were mainly expressed by immune cells. Correlation analysis shows the immune factors and drug responses associated with IKZF3 expression. In conclusion, the present study is the first, to our knowledge, to identify a pan-cancer genomic signature of the Ikaros gene family among different cancers. Expression of these family members, particularly high levels of IKZF3, indicate positive immunological status and beneficial clinical outcomes of SKCM. IKZF3 may therefore serve as potential targets for immunotherapy of melanoma.

The m6A-methylated mRNA pattern and the activation of the Wnt signaling pathway under the hyper-m6A-modifying condition in the keloid.

Purpose: The present study was carried out to investigate the global m6A-modified RNA pattern and possible mechanisms underlying the pathogenesis of keloid. Method: In total, 14 normal skin and 14 keloid tissue samples were first collected on clinics. Then, three samples from each group were randomly selected to be verified with the Western blotting to determine the level of methyltransferase and demethylase. The total RNA of all samples in each group was isolated and subjected to the analysis of MeRIP sequencing and RNA sequencing. Using software of MeTDiff and htseq-count, the m6A peaks and differentially expressed genes (DEGs) were determined within the fold change >2 and p-value < 0.05. The top 10 pathways of m6A-modified genes in each group and the differentially expressed genes were enriched by the Kyoto Encyclopedia of Genes and Genomes signaling pathways. Finally, the closely associated pathway was determined using the Western blotting and immunofluorescence staining. Results: There was a higher protein level of WTAP and Mettl3 in the keloid than in the normal tissue. In the keloid samples, 21,020 unique m6A peaks with 6,573 unique m6A-associated genetic transcripts appeared. In the normal tissue, 4,028 unique m6A peaks with 779 m6A-associated modified genes appeared. In the RNA sequencing, there were 847 genes significantly changed between these groups, transcriptionally. The genes with m6A-methylated modification and the upregulated differentially expressed genes between two tissues were both mainly related to the Wnt signaling pathway. Moreover, the hyper-m6A-modified Wnt/ß-catenin pathway in keloid was verified with Western blotting. From the immunofluorescence staining results, we found that the accumulated fibroblasts were under a hyper-m6A condition in the keloid, and the Wnt/ß-Catenin signaling pathway was mainly activated in the fibroblasts. Conclusion: The fibroblasts in the keloid were under a cellular hyper-m6A-methylated condition, and the hyper-m6A-modified highly expressed Wnt/ß-catenin pathway in the dermal fibroblasts might promote the pathogenesis of keloid.

Development and validation of a flexible DNA extraction (PAN) method for liquid biopsy of multiple sample types.

BACKGROUND: Liquid biopsy is gaining increasing popularity in cancer screening and diagnosis. However, there is no relatively mature DNA isolation method or commercial kit available that is compatible with different LB sample types. This study developed a PAN-sample DNA isolation method (PAN method) for liquid biopsy samples. METHODS: The PAN method has two key steps, including biosample-specific pretreatments for various LB sample types and high concentration guanidine thiocyanate buffer for lysis and denaturation procedure. Subsequently, the performance of PAN method was validated by a series of molecular analyses. RESULTS: The PAN method was used to isolate DNA from multiple sample types related to LB, including plasma, serum, saliva, nasopharyngeal swab, and stool. All purified DNA products showed good quality and high quantity. Comparison of KRAS mutation analysis using DNA purified using PAN method versus QIAamp methods showed similar efficiency. Epstein-Barr virus DNA was detected via Q-PCR using DNA purified from serum, plasma, nasopharyngeal swab, and saliva samples collected from nasopharyngeal carcinoma patients. Similarly, methylation sequencing of swab and saliva samples revealed good coverage of target region and high methylation of HLA-DPB1 gene. Finally, 16S rDNA gene sequencing of saliva, swab, and stool samples successfully defines the relative abundance of microbial communities. CONCLUSIONS: This study developed and validated a PAN-sample DNA isolation method that can be used for different LB samples, which can be applied to molecular epidemiological research and other areas.

Metformin Attenuates Cyclosporine A-induced Renal Fibrosis in Rats.

BACKGROUND: The aim of the present study was to investigate the therapeutic potential of metformin in preventing cyclosporine A (CsA)-induced nephrotoxicity. METHODS: Three groups of adult male Sprague-Dawley rats were treated with vehicle, CsA, and CsA + metformin for 4 weeks following 1 week on low sodium diet, respectively. At the end of treatment, all animals were euthanized, and the samples of kidney, urine, and blood were collected for functional, morphological, and molecular biological evaluation. RESULTS: Metformin effectively prevented CsA-induced renal dysfunction with increased creatinine clearance rate and reduced blood urea nitrogen and serum creatinine, as well as less proteinuria in comparison to the CsA group. Morphologically, metformin ameliorated CsA-induced renal fibrosis and tissue collapse in the areas of arteries, glomeruli, and proximal tubules. We further demonstrated that the antifibrotic effects of metformin in kidneys treated with CsA were associated with decreased phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). CONCLUSIONS: In conclusion, our study revealed new therapeutic potential of metformin to attenuate calcineurin inhibitor-induced renal fibrosis, which was closely related to the suppression of MEK/ERK1/2 pathway.