Correlation between gut microbiota and glucagon-like peptide-1 in patients with gestational diabetes mellitus.

BACKGROUND: Gestational diabetes mellitus (GDM) places both the mother and offspring at high risk of complications. Increasing evidence suggests that the gut microbiota plays a role in the pathogenesis of GDM. However, it is still unclear whether the gut microbiota is related to blood biochemical traits, particularly glucagon-like peptide-1 (GLP-1), in GDM patients. AIM: To explore the correlation between the gut microbiota and blood biochemical traits, particularly GLP-1, in GDM patients. METHODS: The V4 region of the 16S ribosomal ribonucleic acid (rRNA) gene was sequenced based on the fecal samples of 35 pregnant women with GDM and was compared to that of 25 pregnant women with normal glucose tolerance (NGT). RESULTS: The results showed that Ruminococcaceae_UCG-002, Ruminococcaceae_UCG-005, Clostri-dium_sensu_stricto_1, and Streptococcus were more abundant in the NGT group than in the GDM group. Bacteroides and Lachnoclostridium were more abundant in the GDM group than in the NGT group. Spearman's correlation analysis was performed to identify the relationships between microbiota genera and blood biochemical traits. Paraprevotella, Roseburia, Faecalibacterium, and Ruminococcaceae_UCG-002 were significantly negatively correlated with glucose. Ruminococcaceae_UCG-002 was significantly negatively correlated with hemoglobin A1c. Bacteroides was significantly positively correlated with glucose. Sutterella, Oscillibacter, and Bifidobacterium were significantly positively correlated with GLP-1. A random forest model showed that 20 specific genera plus glucose provided the best discriminatory power, as indicated by the area under the receiver operating characteristic curve (0.94). CONCLUSION: The results of this study reveal novel relationships between the gut microbiome, blood bio-chemical traits, particularly GLP-1, and GDM status. These findings suggest that some genera are crucial for controlling blood glucose-related indices and may be beneficial for GDM treatment. Alteration in the microbial composition of the gut may potentially serve as a marker for identifying individuals at risk of GDM.

Decellularized matrix could affect the proliferation and differentiation of periodontal ligament stem cells in vitro.

OBJECTIVE AND BACKGROUND: Recently, decellularized matrix (DCM) is considered as a new biomaterial for tissue regeneration. To explore the possible application of DCM in periodontal regeneration, the effect of DCM from three different cells on the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs) was investigated. METHODS: DCM derived from human periodontal ligament cells (PDLCs), dental pulp cells (DPCs), and gingival fibroblasts (GFs) were fabricated using Triton X-100/NH4 OH combined with DNase I. Allogeneic PDLSCs were cultured on PDLC-DCM, DPC-DCM, and GF-DCM, respectively. The proliferative capacity of PDLSCs was evaluated by PicoGreen assay kit. The expression of alkaline phosphatase (ALP), runt-related transcription factor-2 (RUNX2), osteocalcin (OCN), collagen I (COL1), periostin (POSTN), and cementum protein 1 (CEMP1) were detected by qRT-PCR and western blotting. RESULTS: PDLC-DCM, DPC-DCM, and GF-DCM had similar and integrated networks of extracellular matrix, as well as significantly decreased DNA content. Compared with control group in which PDLSCs were directly seeded in culture plates, PDLC-DCM, DPC-DCM, and GF-DCM promoted the proliferation of re-seeded PDLSCs. Additionally, PDLSCs on DCM exhibited higher mRNA and protein expression levels of ALP, RUNX2, OCN, and COL1. The expression of POSTN in PDLC-DCM group was significantly higher than control group at both mRNA and protein levels. CONCLUSIONS: PDLC-DCM, DPC-DCM, and GF-DCM could enhance the proliferation of PDLSCs. PDLC-DCM facilitated osteogenic differentiation and periodontal ligament differentiation of PDLSCs, while DPC-DCM and GF-DCM promoted osteogenic differentiation.

Regeneration potential of decellularized periodontal ligament cell sheets combined with 15-deoxy-Δ12,14-prostaglandin J2 nanoparticles in a rat periodontal defect.

Periodontitis is a chronic inflammatory disease characterized by loss of attachment and destruction of the periodontium. Decellularized sheet, as an advanced tissue regeneration engineering biomaterial, has been researched and applied in many fields, but its effects on periodontal regeneration remain unclear. In this study, the biological properties of decellularized human periodontal ligament cell (dHPDLC) sheets were evaluated in vitro. Polycaprolactone/gelatin (PCL/GE) nanofibers were fabricated as a carrier to enhance the mechanical strength of the dHPDLC sheet. 15-deoxy-[Formula: see text]-prostaglandin J2 (15d-PGJ2) nanoparticles were added for anti-inflammation and regeneration improvement. For in vivo analysis, dHPDLC sheets combined with 15d-PGJ2 nanoparticles, with or without PCL/GE, were implanted into rat periodontal defects. The periodontal regeneration effects were identified by microcomputed tomography (micro-CT) and histological staining, and immunohistochemistry. The results revealed that DNA content was reduced by 96.6%. The hepatocyte growth factor, vascular endothelial growth factor, and basic fibroblast growth factor were preserved but reduced. The expressions or distribution of collagen I and fibronectin were similar in dHPDLC and nondecellularized cell sheets. The dHPDLC sheets maintained the intact structure of the extracellular matrix. It could be recellularized by allogeneic human periodontal stem ligament cells and retain osteoinductive potential. Newly formed bone, cementum, and PDL were observed in dHPDLC sheets combined with 15d-PGJ2 groups, with or without PCL/GE nanofibers, for four weeks post-operation in vivo. Bringing together all these points, this new construct of dHPDLC sheets can be a potential candidate for periodontal regeneration in an inflammatory environment of the oral cavity.

MOFs assembled from C3 symmetric ligands: structure, iodine capture and role as bifunctional catalysts towards the oxidation-Knoevenagel cascade reaction.

Three new NiII/CoII-metal organic frameworks were self-assembled by the reaction of C3 symmetric 1,3,5-tribenzoic acid (H3BTC) and 2,4,6-tris(4-pyridyl)-1,3,5-triazine (4-TPT) ligands and NiII/CoII salts under solvothermal conditions. Isomorphous MOF1 and MOF2 exhibit a 3D pillar-layer framework based on binuclear M2(OH)(COO)2 units connected by tritopic BTC3- and 4-TPT ligands with a novel (3,5)-connected topology net. MOF3 displays a 3-fold interpenetrated 3D network exhibiting a (3,4)-connected topology net. The porous MOF3 can reversibly take up I2. The activated MOFs contain both Lewis acid (NiII center) and basic (uncoordinated pyridyl or carboxylic groups) sites, and act as bifunctional acid-base catalysts. The catalytic measurements demonstrate that the activated MOF3 exhibits good activities for benzyl alcohol oxidation and the Knoevenagel reaction and can be recycled and reused for at least four cycles without losing its structural integrity and high catalytic activity. Thus, the catalytic properties for the oxidation-Knoevenagel cascade reaction have also been studied.

Mechanism and origins of regioselectivities of Rh-catalyzed alkenylation of allylbenzenes.

Rhodium-catalyzed alkenylation of allylbenzene derivatives via C-C bond activation provides an unprecedented access to alkenylation products with remarkable regioselectivities. Using DFT calculations, we elucidate the reaction mechanism and the origins of the regioselectivity.

AKT2 is involved in the IL­17A­mediated promotion of differentiation and calcification of murine preosteoblastic MC3T3­E1 cells.

Interleukin (IL)­17A exhibits pleiotropic biological activities and serves a role in the progression of periodontitis. However, data describing the association between IL­17 and osteogenesis are not conclusive. It was previously demonstrated that RAC­ß serine/threonine protein kinase (AKT2)­specific knockdown in MC3T3­E1 cells weakened osteogenic effects. The role of AKT2 in the regulation of IL­17A for osteoblast differentiation and calcification remains unclear. The MTT method was adopted in the present study to assess cell proliferation; cell cycle distribution was analyzed by flow cytometry. Following osteogenic induction treatment, the involvement of phosphatidylinositol 3­kinase (PI3K) and phosphorylated­PI3K was evaluated by western blotting. The effects of IL­17A on osteogenesis­associated markers, including Runt­related transcription factor 2 (Runx­2), alkaline phosphatase (ALP) and osteocalcin (OCN) were evaluated by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) analysis. An ALP activity assay and Alizarin Red S staining were used to assess the differentiation and calcification functions. AKT2 knockdown inhibited MC3T3­E1 cell proliferation, inducing significantly increased G0/G1 cell counts, and reduced S and G2/M cell numbers. IL­17A exerted no significant effects. The protein levels of p­PI3K, gene expression levels of IL­17A, Runx­2, ALP and OCN, and relative ALP activity and calcification areas were increased in the induction group, and these effects were markedly promoted by treatment with IL­17A. AKT2 knockdown in MC3T3­E1 cells resulted in reduced IL­17A­induced differentiation and calcification, although it was not completely inhibited. The results of the present study suggested that AKT2 signaling was required for MC3T3­E1 cell proliferation. IL­17A promoted osteoblast differentiation and calcification in a partly AKT2­dependent manner in MC3T3­E1 cells in vitro, possibly reflecting compensation by other signaling pathways. The results of the present study may offer novel perspectives to guide the clinical strategy for the prevention and treatment of periodontitis.

Effect of 15-Deoxy-Δ12,14-prostaglandin J2Nanocapsules on Inflammation and Bone Regeneration in a Rat Bone Defect Model.

BACKGROUND: 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), one of the major metabolites from prostaglandin D2 in arachidonic acid metabolic pathway, has potential anti-inflammatory properties. The objective of this study was to explore the effects of 15d-PGJ2-loaded poly(D,L-lactide-co-glycolide) nanocapsules (15d-PGJ2-NC) on inflammatory responses and bone regeneration in local bone defect. METHODS: The study was conducted on 96 Wistar rats from June 2014 to March 2016. Saline, unloaded nanoparticles, free 15d-PGJ2or 15d-PGJ2-NC, were delivered through a collagen vehicle inside surgically created transcortical defects in rat femurs. Interleukin-6 (IL-6), interleukin-1 beta (IL-1ß), and tumor necrosis factor-alpha (TNF-α) levels in the surrounding soft tissue were analyzed by Western blot and in the defect by quantitative real-time polymerase chain reaction over 14 days. Simultaneously, bone morphogenetic protein-6 (BMP-6) and platelet-derived growth factor-B (PDGF-B) messenger RNA (mRNA) in the defect were examined. New bone formation and EphrinB2 and osteoprotegerin (OPG) protein expression in the cortical defect were observed by Masson's Trichrome staining and immunohistochemistry over 28 days. Data were analyzed by one-way analysis of variance. Least-significant difference and Dunnett's T3 methods were used with a bilateral P< 0.05. RESULTS: Application of l5d-PGJ2-NC (100 µg/ml) in the local bone defect significantly decreased IL-6, IL-1ß, and TNF-α mRNA and protein, compared with saline-treated controls (P < 0.05). l5d-PGJ2-NC upregulated BMP-6 and PDGF-B mRNA (P < 0.05). New bone formation was observed in the cortical defect in l5d-PGJ2-NC-treated animals from 7th day onward (P < 0.001). Expression of EphrinB2 and OPG presented early on day 3 and persisted through day 28 in 15d-PGJ2-NC group (P < 0.05). CONCLUSION: Stable l5d-PGJ2-NC complexes were prepared that could attenuate IL-6, IL-1ß, and TNF-α expression, while increasing new bone formation and growth factors related to bone regeneration.

Th17 and Th1 Lymphocytes Are Correlated with Chronic Periodontitis.

T cells are involved in the homeostasis of periodontal tissues and mediate bone loss in periodontitis, but the involvement of T-helper cells in chronic periodontitis (CP) in a Chinese population is still unclear. This study aimed to assess the distribution of peripheral and local T helper (Th17) and Th1 in CP. Sixty-eight patients with CP and 43 healthy controls were recruited from April 2012 to July 2014 at the Department of Stomatology, People's Hospital of Xinjiang Uygur Autonomous Region (China). The proportions of Th17 (CD3(+)CD4(+)IL-17(+)) and Th1 (CD3(+)CD4(+)IFN-γ(+)) T-cells in peripheral blood samples were assessed by flow cytometry. Immunohistochemistry was used to quantify interleukin-17 (IL-17) and interferon-gamma (IFN-γ) protein levels in gingival biopsy samples. mRNA levels of IL-17, IFN-γ RORγt, and T-bet in gingival biopsy samples were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The proportions of circulating Th17 cells and Th1 cells were both more abundant in CP patients than in controls (Th17: 1.05% ± 0.87% vs. 0.62% ± 0.49%, P < 0.01; Th1: 13.93% ± 7.94% vs. 8.22% ± 4.50%, P < 0.001). Positive correlations were obtained between the proportion of circulating Th17 cells and probing depth (PD) (r = 0.320, P = 0.001) and between the proportion of circulating Th1 cells and PD (r = 0.372, P < 0.001). IL-17 and IFN-γ protein levels in gingival biopsy samples were markedly increased in CP compared to controls (both P < 0.05). Relative IFN-γ, IL-17A, and T-bet mRNA levels in CP biopsies were higher compared to controls (all P < 0.05). These results suggest that elevated peripheral and local Th17 and Th1 cells might be involved in the pathogenesis of CP.

Cytokine levels in plasma and gingival crevicular fluid in chronic periodontitis.

PURPOSE: To evaluate the Th1/Th2/Th17 cytokine levels in plasma and gingival crevicular fluid (GCF) from chronic periodontitis patients and healthy controls. METHODS: The concentration of interleukin-2 (IL-2), IL-4, IL-6, IL-10, IL-17, TNF, and IFN-γ were determined using a flow cytometric multiplex immunoassay (CBA), and was compared between the periodontitis group and the healthy group. Spearman rho coefficient was used to correlate cytokines in GCF in the periodontitis group and the healthy group, respectively. RESULTS: Comparisons of two groups of Th1/Th2/Th17 cytokine levels in plasma and GCF showed no statistically significant differences (P > 0.05), except Th17 (IL-17) level in plasma that was higher in the periodontitis group than the healthy group (P < 0.05). A stronger correlation between IL-17/IL-4 and IL-17/IL-10 was observed in periodontitis patients than in healthy controls.

PI3K/AKT pathway involvement in the osteogenic effects of osteoclast culture supernatants on preosteoblast cells.

This study aimed to investigate the ability of osteoclasts during bone resorption activities to regulate the differentiation and calcification of osteoblast precursor cells. The bone resorption model was established using in vitro cortical bone slices and mouse RAW264.7 cells, which were differentiated into osteoclasts by stimulation with the receptor activator of nuclear factor-κB ligand and macrophage colony-stimulating factor. Tartrate-resistant acid phosphatase (TRAP) staining, reverse transcriptase-polymerase chain reaction (RT-PCR), and scanning electron microscopy (SEM) were used to detect osteoclast differentiation. The osteoblast precursor cell line MC3T3-E1 was cultured with the bone resorption supernatant (BRS). Involvement of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway in osteogenesis was evaluated by Western blotting, RT-PCR, and ELISA analysis of markers of the early (runt-related transcription factor-2 and alkaline phosphatase) and late (osteocalcin [OCN]) stages of osteogenesis, and Alizarin Red S staining of matrix mineralization. TRAP staining, RT-PCR, and SEM analysis demonstrated the successful establishment of the bone resorption model. Osteoclast BRS effectively increased the differentiation and calcification of MC3T3-E1 cells. Western blot analysis indicated that the BRS enhanced AKT and p-AKT expression levels in MC3T3-E1 cells. Following AKT2 knockdown and treatment with the PI3K/AKT pathway inhibitor LY294002, the expression of OCN in MC3T3-E1 cells was decreased (p<0.05), as was the calcification area (p<0.05). The data obtained in this study indicated that the osteoclast bone resorption medium promoted the differentiation and calcification of MC3T3-E1 cells and that the PI3K/AKT pathway played a role in this process.