Periodontitis is a common oral disease characterized by progressive alveolar bone resorption and inflammation of the periodontal tissues. Dimethyl fumarate (DMF) has been used in the treatment of various immune-inflammatory diseases due to its excellent anti-inflammatory and antioxidant functions. Here, we investigated for the first time the therapeutic effect of DMF on periodontitis. In vivo studies showed that DMF significantly inhibited periodontal destruction, enhanced mitophagy, and decreased the M1/M2 macrophage ratio. In vitro studies showed that DMF inhibited macrophage polarization toward M1 macrophages and promoted polarization toward M2 macrophages, with improved mitochondrial function, inhibited oxidative stress, and increased mitophagy in RAW 264.7 cells. Furthermore, DMF increased intracellular mitochondrial Tu translation elongation factor (TUFM) levels to maintain mitochondrial homeostasis, promoted mitophagy, and modulated macrophage polarization, whereas TUFM knockdown decreased the protective effect of DMF. Finally, mechanistic studies showed that DMF increased intracellular TUFM levels by protecting TUFM from degradation via the ubiquitin-proteasomal degradation pathway. Our results demonstrate for the first time that DMF protects mitochondrial function and inhibits oxidative stress through TUFM-mediated mitophagy in macrophages, resulting in a shift in the balance of macrophage polarization, thereby attenuating periodontitis. Importantly, this study provides new insights into the prevention of periodontitis.
Dimethyl Fumarate/pharmacology* ; Mitophagy/drug effects* ; Animals ; Mice ; Macrophages/metabolism* ; Periodontitis/prevention & control* ; RAW 264.7 Cells ; Oxidative Stress/drug effects* ; Peptide Elongation Factor Tu/metabolism* ; Mice, Inbred C57BL ; Male ; Mitochondria/drug effects*

Objective To explore the status of mutations of k-ras gene in colorectal cancer (CRC) patients and to make theory preparation for the k-ras mutation detection in diagnosis laboratory. Methods The Genomic DNA was extracted, mutation analysis of k-ras was detected by PCR and bi-direction sequencing in the 56 specimens. Results Rate of k-ras mutation was 46.63 % (26/56) including 76.92 % (20/26) located at codon 12, and 23.08 %(6/26) located at codon 13, and no mutation was found at both codons simultaneously. G>A transition is the most common type of k-ras mutation,GGT>GAT (G12D) is the predominant mutation at codon 12 and GGOGAC (G13D) at codonl3. Chi-square analysis revealed the k-ras mutation was significantly correlated to the gender of the patients. Conclusion The k-ras mutation is mainly located at the codon 12, G>A transition is the most type of k-ras mutation in CRC. k-ras mutation seems to correlate with the gender of CRC patients.