Neutrophils are involved in early bone formation during midpalatal expansion.

OBJECTIVE: Midpalatal expansion (MPE) is routinely employed to treat transverse maxillary arch deficiency. Neutrophils are indispensable for recruiting bone marrow stromal cells (BMSCs) at the initial stage of bone regeneration. This study aimed to explore whether neutrophils participate in MPE and how they function during bone formation under mechanical stretching. MATERIALS AND METHODS: The presence and phenotype of neutrophils in the midpalatal suture during expansion were detected by flow cytometry and immunofluorescence staining. The possible mechanism of neutrophil recruitment and polarization was explored in vitro by exposing vascular endothelial cells (VECs) to cyclic tensile strain. RESULTS: The number of neutrophils in the distracted suture peaked on Day 3, and N2-type neutrophils significantly increased on Day 5 after force application. The depletion of circulatory neutrophils reduced bone volume by 43.6% after 7-day expansion. The stretched VECs recruited neutrophils via a CXCR2 mechanism in vitro, which then promoted BMSC osteogenic differentiation through the VEGFA/VEGFR2 axis. Consistently, these neutrophils showed higher expression of canonical N2 phenotype genes, including CD206 and Arg1. CONCLUSIONS: These results suggested that neutrophils participated in early bone formation during MPE. Based on these findings, we propose that stretched VECs recruited and polarized neutrophils, which, in turn, induced BMSC osteogenic differentiation.

Identify GADD45G as a potential target of 4-methoxydalbergione in treatment of liver cancer: bioinformatics analysis and in vivo experiment.

BACKGROUND: The growth arrest and DNA damage-inducible gene gamma (GADD45G), an important member of GADD45 family, has been connected to the development of certain human cancers. Our previous studies have confirmed that GADD45G expression could be upregulated by 4-methoxydalbergione (4MOD) in liver cancer cells, but its potential pathological role in hepatocellular carcinoma (HCC) has not been fully understood. This study aimed to determine potential role of GADD45G in HCC, and the effects of 4-methoxydalbergione (4MOD) on the regulation of GADD45G expression in vivo were also analyzed. METHODS: Publicly available data and in-house immunohistochemistry (IHC) experiments were utilized to explore the expression profiles and clinical significance of GADD45G in HCC samples. Functional enrichment analysis based on GADD45G co-expression genes was used to excavate the molecular mechanism of GADD45G in HCC. We also conducted in vivo experiment on BALB/c nude mice to excavate the inhibitory effect of 4MOD on HCC and to evaluate the differences in the expression of GADD45G in xenograft tissues between the 4MOD-treated and untreated groups. RESULTS: GADD45G displayed significant low expression in HCC tissues. Downregulated expression of GADD45G was positively correlated with some high risk factors in HCC patients and predicted worse prognosis of HCC patients. There was a close association of GADD45G mRNA expression and immune cells, including neutrophils, NK cells, CD8 T cells, and macrophages. Co-expressed genes of GADD45G were involved in several pathways including cell cycle, carbon metabolism, and peroxisome. 4MOD could significantly suppress the growth of HCC in vivo, and this inhibitory effect was dependent on the upregulation of GADD45G expression. CONCLUSION: GADD45G expression can be used as a new clinical biomarker for HCC and GADD45G may be a potential target for the anti-cancer effect of 4MOD in liver cancer.

Characterization of a new endo-type polyM-specific alginate lyase from Pseudomonas sp.

An alginate lyase gene, algA, encoding a new poly ß-D-mannuronate (polyM)-specific alginate lyase AlgA, was cloned from Pseudomonas sp. E03. The recombinant AlgA with (His)6-tag, consisting of 364 amino acids (40.4 kDa),was purified using Ni-NTA Sepharose. The purified lyase had maximal activity (222 EU/mg) at pH 8 and 30 °C and also maintained activity between pH 7-9 and below 45 °C. It exclusively and endolytically depolymerized polyM by ß-elimination into oligosaccharides with degrees of polymerization (DP) of 2-5. Due to its high substrate specificity, AlgA could be a valuable tool for production of polyM oligosaccharides with low DP and for determining the fine structure of alginate.

Molecular cloning and characterization of two major endoglucanases from Penicillium decumbens.

Two major endoglucanase genes (cel7B and cel5A) were cloned from Penicillium decumbens 114-2 using the method of modified thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR). The result of Southern blotting suggested that P. decumbens has a single copy of the cel5A gene and a single copy of cel7B gene in its chromosomal DNA. The expression level of cel5A and cel7B were determined by means of real-time quantitative PCR, suggesting that two genes were coordinately expressed and repressed by glucose and induced by cellulose. Both endoglucanase genes were expressed in Saccharomyces cerevisiae and the recombinant proteins were purified. The recombinant Cel7B and Cel5A were both optimal active at 60 C and pH 4.0. The recombinant Cel7B showed more than 8-fold, 30-fold, 5-fold higher enzyme activity towards carboxymethyl cellulose, barely beta-glucan and PASC respectively in comparison with that of Cel5A. However, their activities toward pNPC and Avicel were minor difference. The result suggested that Cel7B is a strict endoglucanase, while Cel5A show processivity because of its relative higher ability to hydrolyze the crystal cellulose.