Blocking Gremlin1 inhibits M1 macrophage polarization through Notch1/Hes1 signaling pathway in apical periodontitis.

BACKGROUND: Gremlin1 is a multifunctional protein whose expression is demonstrated to be involved in a series of physiology and pathological processes. The association between Gremlin1 and apcial periodontitis (AP) has been established. M1-polarized macrophages are crucial immune cells that exacerbate the progression of apical periodontal inflammatory response, but the function of Gremlin1 during macrophages activation in periapical lesions is still unclear. This study attempts to explore the regulatory effects of Gremlin1 on macrophage polarization on apical periodontitis microenviroment. METHODS: Clinical specimens were used to determine the expression of Gremlin1 in periapical tissues by immunohistochemical (IHC) staining. Then, the disease models of periapical inflammation in rats were established, and adenovirus- associated virus (AAVs) was used to blockade Gremlin1 expression. Lentivirus carrying sh-Gremlin1 particles were used to transfect THP-1 induced M1-subtype macrophages. To assess the expression of associated molecules, Western blot, immunofluorescence staining were performed. RESULTS: Gremlin1 was significantly up-regulated in the periapical tissues of subjects with AP as identified by IHC staining, and positively correlated with levels of M1 macrophage-associated genes. Rats AP model with inhibition of Gremlin1 in periapical lesions exhibited limited infiltration of macrophages and decreased expression of M1 macrophage-related genes in periapical lesions. Furthermore, Gremlin1 blockade substantially decreased the Notch1/Hes1 signaling pathway activation level. The in vitro experiments confirmed the above results. CONCLUSION: Taken together, current study illustrated that the Gremlin1 suppression in periapical lesions inhibited M1 macrophage polarization through Notch1/Hes1 axis. Moreover, Gremlin1 may act as a potential candidate in the treatment of AP.

Transcriptome analysis of gingival tissues of enamel-renal syndrome.

BACKGROUND AND OBJECTIVE: Biallelic loss-of-function mutations of human FAM20A have been known to cause enamel-renal syndrome (ERS), featured by agenesis of dental enamel, nephrocalcinosis, and other orodental abnormalities, including gingival hyperplasia. However, while the histopathology of this gingival anomaly has been analyzed, its underlying molecular mechanism remains largely unknown. This study aimed to unravel the pathogenesis of gingival hyperplasia in ERS. METHODS: Whole-exome sequencing was conducted for an ERS case. Transcriptome analyses, using RNA sequencing, of the patient's gingiva were performed to unravel dysregulated molecules and aberrant biological processes underlying the gingival pathology of ERS, which was further confirmed by histology and immunohistochemistry. RESULTS: Two novel frameshift FAM20A mutations in Exon 1 (g.5417delG; c.129delG; p.Cys44Alafs*101) and Exon 5 (g.62248_62249delAG; c.734_735delAG; p.Glu245Glyfs*11) were identified. Transcriptional profiling of patient's gingival tissue revealed a total of 1683 genes whose expression had increased (1129 genes) or decreased (554 genes) at least 2-fold compared to control gingival tissues. There were 951 gene ontology (GO) terms of biological process being significantly over-represented or under-represented. While GOs involved in extracellular matrix organization, angiogenesis, biomineralization, and epithelial cell proliferation appeared to be activated in ERS gingiva, genes related to keratinocyte differentiation, epithelial development, and keratinization were of decreased expression. FAM20A immunohistochemistry revealed a strong reactivity at the suprabasal layers of epithelium in control gingiva but showed a significantly diminished and scattered signal in ERS tissues. For genes showing significant over-expression in the transcriptome analyses, namely ALPL, SPARC, and ACTA2, an increased immunoreactivity was observed. CONCLUSION: Our results unraveled a potential role for FAM20A in homeostasis of both gingival epithelium and connective tissues.

A tough and bioadhesive injectable hydrogel formed with maleimidyl alginate and pristine gelatin.

Injectable hydrogels have wide applications in clinical practice. However, the development of tough and bioadhesive ones based on biopolymers, along with biofriendly and robust crosslinking strategies, still represents a great challenge. Herein, we report an injectable hydrogel composed of maleimidyl alginate and pristine gelatin, for which the precursor solutions could self-crosslink via mild Michael-type addition without any catalyst or external energy upon mixing. This hydrogel is tough and bioadhesive, which can maintain intactness as well as adherence to the defect of porcine skin under fierce bending and twisting, warm water bath, and boiling water shower. Besides, it is biocompatible, bioactive and biodegradable, which could support the growth and remodeling of cells by affording an extracellular matrix-like environment. As a proof of application, we demonstrate that this hydrogel could significantly accelerate diabetic skin wound healing, thereby holding great potential in healthcare.

[Study on separation and purification of total alkaloids and mesaconitine with X - 5 macroporous resin].

OBJECTIVE: To study systematically the factors which affect separation and purification of the total alkaloids and mesaconitine with X -5 macroporous resin. METHOD: With the content of the total alkaloids and mesaconitine as parameters, the optimum condition of absorption and elution were studied in the process of the purification with X -5 macroporous resin. RESULT: The X - 5 macroporous resin yielded the best separating efficiency when the concentration of the extracted solution was 1 g raw material per 1 mL, pH 12.0, the absorptive time of 6 hour and the volume of 95% ethanol (7BV pH 8) as the eluant; X -5 macroporous resins was used five times in a reproducible way. The rate of extraction and content of the total alkaloid were 80% and 30% respectively after purification with X - 5 macroprous resin. CONCLUSION: The method can increase the purity of mesaconitine and total alkaloids.

[Expression of proto-oncogenes c-fos and c-jun in osteoblasts activated by excessive fluoride].

OBJECTIVE: To study expression of proto-oncogenes c-fos and its accompanying gene c-jun in osteoblasts activated by action of excessive fluoride in vivo and in vitro. METHODS: Experimental Wistar rats were exposed to sodium fluoride (NaF) added to their drinking water, and NaF was also added in cell culture supernatant for osteoblast-like cells in vitro. Expression of both mRNA and protein of c-fos and c-jun in bone-tissue of rats with chronic fluorosis and cultured osteoblast-like cells were determined by hybridization in situ, Western blot and immunohistochemistry at varied time periods after exposure. RESULTS: Sodium fluoride could stimulate the proliferation of osteoblast in rats with chronic fluorosis and induce expression of both c-fos and c-jun in all envelops of the spine bone, as compared with its control group. Value of optical absorption in mRNA expression of c-fos and c-jun was 139.63 and 126.37, respectively, in rats with NaF plus high-calcium, significantly lower than that in control group with high-calcium only (107.74 and 117.48, respectively) (P < 0.001). Immunohistochemical analysis showed that protein level of c-fos and c-jun was significantly higher in rats with NaF plus high-calcium than that in control rats with high-calcium only, with values of optical absorption of 139.16, 131.15, 149.98 and 149.19 (P < 0.05), respectively, and protein level of c-fos and c-jun was significantly higher in rats with NaF plus low-calcium than that in control rats with low-calcium only, with values of optical absorption of 117.24, 111.46, 132.46 and 129.79 (P < 0.05), respectively. Western blotting showed that level of protein expression of c-fos and c-jun in periosteal osteoblasts was significantly higher in all rat groups with NaF than that in all control groups, with values of optical absorption of 123.32, 116.60, 115.97 and 108.30, respectively. mRNA expression of c-fos and c-jun in osteoblast-like cells treated with NaF for 12 h increased obviously, and remained at high level 48 h after exposure, with values of optical absorption of 114.80, 161.14, 118.20, and 150.41, respectively, as compared with that in control group (P < 0.001 and P < 0.05). CONCLUSIONS: Exposure to excessive fluoride could stimulate activation and proliferation of both osteoblasts in rats and cultured osteoblast-like cells in vitro, and cause enhanced expression of mRNA and protein of both c-fos and c-jun. Over-expression of c-fos could play an important role in development and proliferation of skeletal lesions in rats with chronic fluorosis.

[Association between -590C/T polymorphisms of interleukin-4 gene and chronic periodontitis: a meta-analysis].

PURPOSE: To evaluate the relationship between -590C/T polymorphisms of interleukin-4 gene and chronic periodontitis using meta-analysis. METHODS: The selected studies were pooled from eight major electronic databases for case-control study. To gain a more precise estimation of the relationship, a stratified meta-analysis with two subgroups was performed according to the races. Heterogeneity, publication bias and sensitivity analysis were also explored. RESULTS: Totally 8 studies were recruited. Total sample sizes for chronic periodontitis and control groups were 628 and 717, respectively. Meta-analysis showed that both -590C/T polymorphisms and allele frequency were not significantly associated with chronic periodontitis. In subgroup analysis, a significant association of increased chronic periodontitis risk and T allele was found. The results also indicated a significant correlation between -590C/T polymorphisms of IL-4 and Caucasian who suffered from chronic periodontitis(C vs.T: OR=0.71,95% CI=0.56-0.89;CC vs.CT:OR=0.60,95% CI=0.38-0.94;recessive genetic model CC vs.CT+TT:OR=0.61,95% CI=0.42-0.88), further analysis of the results showed the CC genotype was about 39% less likely to have chronic periodontitis than the CT and TT genotype in Caucasian individuals.However, these significant associations was not found in Asian group. CONCLUSIONS: The meta-analysis suggests there may be an important effect of single nucleotide polymorphisms (SNPs) in the promoter region of IL-4 gene on the pathogenesis of chronic periodontitis in Caucasian. This warrants further investigation in larger studies and multi-race epidemiological to evaluate the results.

[The reliability and accuracy of the digital models reconstructed by cone-beam computed tomography].

PURPOSE: To evaluate the reliability of the digital models scanned by cone-beam computed tomography (CBCT). METHODS: Forty plaster models of patients with orthodontic treatment were selected. These plaster models were scanned and measured by 3DX cone beam CT, compared with manual measurement via concordance correlation coefficient (CCC) and mean difference (MD). RESULTS: The CCC of all the measurement was from 0.847 to 0.993. The value of MD of all the measurement was below 0.25mm except CFF6, PWF5 and PWF6, which was 0.34mm, 0.63mm and 1.49mm, respectively. CONCLUSIONS: The reliability and accuracy of the digital models scanned by cone-beam CT is very high. The accuracy of measurement of the dental cusp is the highest, the dental fossa is the second, and the lowest point of palatal gingival is the third.