Role of ferroptosis-related genes in periodontitis based on integrated bioinformatics analysis.

BACKGROUND: Cell survival or death is one of the key scientific issues of inflammatory response. To regulate cell death during the occurrence and development of periodontitis, various forms of programmed cell death, such as pyroptosis, ferroptosis, necroptosis, and apoptosis, have been proposed. It has been found that ferroptosis characterized by iron-dependent lipid peroxidation is involved in cancer, degenerative brain diseases and inflammatory diseases. Furthermore, NCOA4 is considered one of ferroptosis-related genes (FRGs) contributing to butyrate-induced cell death in the periodontitis. This research aims to analyze the expression of FRGs in periodontitis tissues and to explore the relationship between ferroptosis and periodontitis. METHOD: Genes associated with periodontitis were retrieved from two Gene Expression Omnibus datasets. Then, we normalized microarray data and removed the batch effect using the R software. We used R to convert the mRNA expression data and collected the expression of FRGs. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), transcription factor (TF) and protein-protein interaction (PPI) network analyses were used. In addition, we constructed a receiver operating characteristic curve and obtained relative mRNA expression verified by quantitative reverse-transcription polymerase chain reaction (PCR). RESULTS: Eight and 10 FRGs related to periodontitis were upregulated and downregulated, respectively. GO analysis showed that FRGs were enriched in the regulation of glutathione biosynthetic, glutamate homeostasis, and endoplasmic reticulum-nucleus signaling pathway. The top TFs included CEBPB, JUND, ATF2. Based on the PPI network analysis, FRGs were mainly linked to the negative regulation of IRE1-mediated unfolded protein response, regulation of type IIa hypersensitivity, and regulation of apoptotic cell clearance. The expression levels of NCOA4, SLC1A5 and HSPB1 using PCR were significantly different between normal gingival samples and periodontitis samples. Furthermore, the diagnostic value of FRGs for periodontitis were "Good". CONCLUSIONS: We found significant associations between FRGs and periodontitis. The present study not only provides a new possible pathomechanism for the occurrence of periodontitis but also offers a new direction for the diagnosis and treatment of periodontitis.

Mesenchymal-to-epithelial transition of osteoblasts induced by Fam20c knockout.

BACKGROUND: Fam20c is intimately related to tissue development and diseases. At present, it has been reported that Fam20c regulates the mineralization of osteoblasts, but there are few reports on other effects. OBJECTIVE: To study the effect of Fam20c on osteoblasts by knocking out the Fam20c gene. METHODS: Fam20c knockout osteoblasts were constructed by transfecting mouse osteoblasts with lentivirus. The proliferation, migration and mineralization of Fam20c knockout cells were detected by CCK-8, scratch test and alizarin red staining assays. The subcellular structure was observed by transmission electron microscopy. RT-PCR was used to detect the differential expression of mesenchymal-to-epithelial transition (MET)-related marker genes and core transcription factors. The differential expression of MET-related proteins was detected by immunofluorescence or Western blot. Transcriptome analysis of Fam20c knockout osteoblasts was performed, and real-time PCR was used to verify transcriptome analysis related to MET. RESULTS: The proliferation ability of osteoblasts was not significantly changed after Fam20c deletion, but the migration ability and mineralization ability were significantly weakened. There were tight junctions between Fam20c knockout cells. The expression of mesenchymal cell marker genes and core transcription factors was significantly decreased, and the expression of epithelial cell marker genes was significantly increased. The expression of mesenchymal cell marker proteins was significantly decreased, and the expression of epithelial cell marker proteins was significantly increased. Multiple signalling molecules and pathways involved in MET have changed. CONCLUSIONS: Knockdown of Fam20c resulted in MET. Fam20c affects the transcription of key factors in osteoblast MET.

Prognostic and immunological role of Fam20C in pan-cancer.

BACKGROUND: The family with sequence similarity 20-member C (Fam20C) kinase plays important roles in physiopathological process and is responsible for majority of the secreted phosphoproteome, including substrates associated with tumor cell migration. However, it remains unclear whether Fam20C plays a role in cancers. Here, we aimed to analyze the expression and prognostic value of Fam20C in pan-cancer and to gain insights into the association between Fam20C and immune infiltration. METHODS: We analyzed Fam20C expression patterns and the associations between Fam20C expression levels and prognosis in pan-cancer via the ONCOMINE, TIMER (Tumor Immune Estimation Resource), PrognoScan, GEPIA (Gene Expression Profiling Interactive Analysis), and Kaplan-Meier Plotter databases. After that, GEPIA and TIMER databases were applied to investigate the relations between Fam20C expression and immune infiltration across different cancer types, especially BLCA (bladder urothelial carcinoma), LGG (brain lower grade glioma), and STAD (stomach adenocarcinoma). RESULTS: Compared with adjacent normal tissues, Fam20C was widely expressed across many cancers. In general, Fam20C showed a detrimental role in pan-cancer, it was positively associated with poor survival of BLCA, LGG, and STAD patients. Specifically, based on TCGA (The Cancer Genome Atlas) database, a high expression level of Fam20C was associated with worse prognostic value in stages T2-T4 and stages N0-N2 in the cohort of STAD patients. Moreover, Fam20C expression had positive associations with immune infiltration, including CD4+ T cells, macrophages, neutrophils, and dendritic cells, and other diverse immune cells in BLCA, LGG, and STAD. CONCLUSION: Fam20C may serve as a promising prognostic biomarker in pan-cancer and has positive associations with immune infiltrates.

Differentiation of human dental pulp stem cells into neuronal by resveratrol.

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. Resveratrol (RSV) is a natural polyphenolic and possesses many biological functions such as anti-inflammatory activity and protection against atherosclerosis and neuroprotective activities. There is increasing evidence showing that RSV plays a pivotal role in neuron protection and neuronal differentiation. In this study, we isolated DPSCs from impacted third molars and investigated whether RSV induces neuronal differentiation of DPSCs. To avoid loss of DPSCs multipotency, all the experiments were conducted on cells at early passages. RT-PCR results showed that RSV-treated DPSCs (RSV-DPSCs) significantly increased the expression of the neuroprogenitor marker Nestin. When RSV-DPSCs were differentiated with neuronal induction media (RSV-dDPSCs), they showed a cell morphology similar to neurons. The expression of neuronal-specific marker genes Nestin, Musashi, and NF-M in RSV-dDPSCs was significantly increased. Immunocytochemical staining and Western blot analysis showed that the expression of neuronal marker proteins, Nestin, and NF-M, was significantly increased in RSV-dDPSCs. Therefore, we have shown that RSV treatment, along with the use of neuronal induction media, effectively promotes neuronal cell differentiation of DPSCs.

[Expression and subcellular localization of (R)- and (S)-specific carbonyl reductases from Candida parapsilosis in Saccharomyces cerevisia].

OBJECTIVE: The (R)- and (S)- specific carbonyl reductases (RCR and SCR) with enhanced green fluorescence protein ( EGFP) were expressed in Saccharomyces cerevisiae W303-1A. By analysis of EGFP expression spectrum, the protein distribution and subcellular localization of two enzymes were determined. METHODS: By SOE-PCR method, the fused genes of RCR and SCR with EGFP were cloned and constructed on an eukaryotic expression vector pYX212, and transformed into S. cerevisiae by electroporation. With fluorescent protein as selection marker, the expression and distribution of RCR and SCR were observed. RESULTS: The EGFP expression in S. cerevisiae cells was observed under the laser scanning confocal microscopy. It was showed that the two enzymes expressed stably in S. cerevisiae and mainly distributed in the intracellular membrane and cytoplasm, while minority were dotted in the center of cells. According to the fluorescent intensity, the expression level of SCR was much higher than that of RCR in S. cerevisiae. The biotransformation results showed that the fused proteins EGFP-RCR and EGFP-SCR reduced 2-hydroxyacetophenone to give (R)- and (S)-1-phenyl-1 ,2-ethanediol (PED) respectively, with the optical purity of 86.6% in a yield of 70.4% for the former enzyme and with the optical purity of 92.3% in a yield of 81.8% for the latter one. DISCUSSION: The fusion of RCR or SCR with EGFP showed no effect in protein conformation and biological activity. When compared with the recombinant Escherichia coli harboring RCR or SCR, the genetically engineered S. cerevisiae had obvious advantages in the biological function. The study provided the solid foundations for visible research of functional expression controlling and subcellular localization of carbonyl reductases.

Carbonyl reductase SCRII from Candida parapsilosis catalyzes anti-Prelog reaction to (S)-1-phenyl-1,2-ethanediol with absolute stereochemical selectivity.

An (S)-specific carbonyl reductase (SCRII) was purified to homogeneity from Candida parapsilosis by following an anti-Prelog reducing activity of 2-hydroxyacetophenone. Peptide mass fingerprinting analysis shows SCRII belongs to short-chain dehydrogenase/reductase family. Its coding gene was cloned and overexpressed in Escherichia coli. The recombinant SCRII displays the similar enzymatic characterization and catalytic properties to SCR. It catalyzes the enantioselective reduction of 2-hydroxyacetophenone to (S)-1-phenyl-1,2-ethanediol with excellent optical purity of 100% in higher yield than SCR. Based on the sequence-structure alignment, several single-point mutations inside or adjacent to the substrate-binding loop or active site were designed. With respect to recombinant native SCRII, the A220 and E228 mutations almost lost enantioselectivity towards 2-hydroxyacetophenone reduction. The catalytic efficiencies (kcat/Km) for the A220 or E228 variants are <7% that of the unmutated enzyme. This work provides an excellent catalyst for enantiopure alcohol preparation and the lethal mutations of A220 and E228 suggest their importance in substrate-binding and/or catalysis.

[Gene cloning and expression of a novel (S)-specific carbonyl reductase].

OBJECTIVE: A novel (S)-specific carbonyl reductase gene (scr II) was cloned from the genome of Candida parapsilosis CCTCC M203011, and its catalytic function for the biotransformation of chiral alcohol was verified. METHODS: The possible carbonyl reductase gene scr II was amplified by PCR method from the C. parapsilosis genome. Using the recombinant Escherichia coli BL21/pET28a-scr II as the catalyst and 2-hydroxyacetophenone as the substrate, the biotransformation was carried out. The optical purity and yield of the final product were investigated by HPLC analysis. The optimal pH and temperature of the reaction were also determined. RESULTS: The gene scr II coded 279 amino acids with an open reading frame of 837 bp. It shared 85% identity with the reported gene scr. By analysis, SCR II contained two typical motifs of the short-chain carbonyl reductase including a Rossmann-fold Thr40-Gly41-(X)3-Gly45-X-Gly47 and a conserved catalytic triad Ser172-(X)n-Tyr187-(X)3-Lys191. SDS-PAGE results showed that SCR II was overexpressed at 30 degrees C after the induction of 0.1 mmol/L IPTG. When the concentration of 2-hydroxyacetophenone was 6 g/L, 10% (w/v) wet recombinant E. coli cells showed excellent performance to give (S)-1-phenyl-1,2-ethanediol with high optical purity of 99.1% enantiomeric excess in a yield of 89.60% under the optimal conditions of pH 5.5 and 35 degrees C. SCR II catalyzed the transformation of (S)-1-phenyl-1, 2-ethanediol more efficiently than SCR. When compared with SCR, its substrate concentration was increased by two-fold, and the optical purity and yield of (S)-1-phenyl-1,2-ethanediol were improved by 10% and 28%, respectively. CONCLUSION: The gene coding for novel carbonyl reductase SCR II was isolated using the molecular cloning technique and its discovery supplied a solid research foundation for chiral alcohol preparation efficiently.

Improved production of (R)-1-phenyl-1,2-ethanediol by a codon-optimized R-specific carbonyl reductase from Candida parapsilosis in Escherichia coli.

An R-specific carbonyl reductase from Candida parapsilosis (CprCR) catalyzes the transformation of (R)-1-phenyl-1,2-ethanediol from 2-hydroxyacetophenone. The gene rcr coding CprCR contains a few codons rarely used by Escherichia coli. In order to improve chiral alcohol production, three codon variants Delta24, aRCR, and mRCR of CprCR were designed through truncation of 4-27 bp disorder sequence at the 5'-terminus or/and adaption of nine rare codons. The effects of codon optimization on enzyme activity, protein production, and biotransformation were studied. Among these three types, the disorder sequence-truncated and rare codon-adapted variant mRCR presents the highest enzyme activity. When compared with CprCR, mRCR showed an increase of 35.6% in the total activity of cell-free extracts. The specific activity of mRCR presented similar increase in the cell-free extract with purified protein, which suggested that the codon optimization caused positive effect on protein productivity of variant enzyme. When microbial cells concentration was 30% (w/v), the molar conversion yield and enantiomeric excess of the mRCR variant reached 86.4% and 93.6%, which were increased 36.5% and 15.8% than those of wild-type at a high substrate concentration of 5 g/L. The work will supply a new method for improving chiral alcohol preparation with codon engineered microorganisms.

[Construction of an enzyme-coupled system consisting of (R)- and (S)-specific carbonyl reductases for one-step preparation of (S)-1-phenyl-1,2-ethanediol].

OBJECTIVE: To prepare (S)-1-phenyl-1,2-ethanediol by a one-step method, we constructed an enzyme coupled system consisting of (R)- and (S)-specific carbonyl reductases in Escherichia coli. METHODS: The genes coding (R)- and (S)-specific carbonyl reductases from Candida parapsilosis were inserted into a co-expression vector pETDuet-1. The positive plasmid was transformed into codon optimized E. coli Rosetta and an enzyme-coupled recombinant strain E. coli Rosetta / pETDuet-rcr-fdh was constructed. When the OD600 value of the culture reached 0.6-0.8, IPTG with a final concentration of 1 mmol/L was added to induce both target proteins at 30 degrees C for 10 h. RESULTS: SDS-PAGE analysis showed that two target enzymes were expressed simultaneously with the relative molecular weights of 37 kDa and 30 kDa. When 5 mol/L Zn2+ was added into a phosphate buffer (pH7.0), the biotransformation results showed that the product (S)-1-phenyl-1,2-ethanediol was produced with the optical purity of 91.3% enantiomeric excess and a yield of 75.9% by E. coli Rosetta/pETDuet-rcr-scr. CONCLUSION: The functions of two redox enzymes were integrated by molecular recombinant technique and a one-step method for preparation of (S)-1-phenyl-1,2-ethanediol was developed through an enzyme-coupled system. The method may supply a new procedure in chiral alcohols preparation.

[Improved expression and catalytic efficiency of (R)-carbonyl reductase in Escherichia coli by secondary structure optimization of mRNA translation initiation region].

To improve the expression level and catalytic efficiency of (R)-carbonyl reductase from Candida parapsilosis in Escherichia coli, we optimized the mRNA secondary structure of (R)-carbonyl reductase gene in translation initiation region (from +1 to +78), and constructed the corresponding variant. The formation of hairpin structure was significantly reduced and the Gibbs free energy was dramatically decreased from -9.5 kcal/mol to -5.0 kcal/mol after optimization. As a result, the expression level of (R)-carbonyl reductase in the variant was increased by 4-5 times and its specific activity in cell-free extract was enhanced by 61.9% compared to the wild-type strain. When using the whole cells as catalyst and 2-hydroxyacetophenone as substrate with a high concentration of 5.0 g/L, the variant showed excellent performance to give (R)-1-phenyl-1, 2-ethanediol with optical purity of 93.1% enantiomeric excess and a yield of 81.8%, which were increased by 27.5% and 40.5% respectively than those of the wild-type. In conclusion, the optimization of mRNA secondary structure in translation initiation region can overcome the steric hindrance of translation startup, promote translation smoothly to acquire high expression of target protein, and favor protein folding correctly to efficiently improve the enzyme specific activity and biotransformation function.