Host sex disparity and viral genotype dependence of the glycosylation level of small Hepatitis B surface protein in patients with HBeAg-positive chronic Hepatitis B.

BACKGROUND: Hepatitis B surface antigen (HBsAg) consists of six components of large/middle/small HBs proteins (L/M/SHBs) with non-glycosylated (ng)- or glycosylated (g)- isomers at sN146 in their shared S domain. g-SHBs plays a crucial role in hepatitis B virus (HBV) secretion. However, the host and viral factors impacting sN146 status in natural HBV infection remain revealed mainly due to the technical difficulty in quantifying g-SHBs and ng-SHBs in serum samples. METHODS: To establish a standardized Western blot (WB) assay (WB-HBs) for quantifying the SHBs isomers in serum samples of 328 untreated hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients with genotype B or C HBV infection. The 1.3-mer HBV genotype B or C plasmids were transiently transfected into HepG2 cells for in vitro study. RESULTS: The median level of ng-SHBs was significantly higher than that of g-SHBs (N = 328) (2.6 vs. 2.0 log10, P < 0.0001). The median g-/ng-SHBs ratio in female patients (N = 75) was significantly higher than that of male patients (N = 253) (0.35 vs. 0.31, P < 0.01) and the median g-/ng-SHBs ratio in genotype C patients (N = 203) was significantly higher than that of the genotype B patients (N = 125) (0.33 vs. 0.29, P < 0.0001). CONCLUSIONS: Our findings suggest that the g-/ng-SHBs ratio is host-sex-biased and viral genotype dependent in treatment naïve patients with HBeAg-positive chronic hepatitis B, which indicates the glycosylation of SHBs could be regulated by both host and viral factors. The change of ratio may reflect the fitness of HBV in patients, which deserves further investigation in a variety of cohorts such as patients with interferon or nucleos(t)ide analogues treatment.

Self-Assembling Peptide RADA16 Nanofiber Scaffold Hydrogel-Wrapped Concentrated Growth Factors in Osteogenesis of MC3T3.

Concentrated growth factors (CGFs) are widely used in surgery with bone grafting, but the release of growth factors from CGFs is rapid. RADA16, a self-assembling peptide, can form a scaffold that is similar to the extracellular matrix. Based on the properties of RADA16 and CGF, we hypothesized that the RADA16 nanofiber scaffold hydrogel could enhance the function of CGFs and that the RADA16 nanofiber scaffold hydrogel-wrapped CGFs (RADA16-CGFs) would perform a good osteoinductive function. This study aimed to investigate the osteoinductive function of RADA16-CGFs. Scanning electron microscopy, rheometry, and ELISA were performed, and MC3T3-E1 cells were used to test cell adhesion, cytotoxicity, and mineralization after administration with RADA16-CGFs. We found that RADA16 endowed with the sustained release of growth factors from CGFs, which can help maximize the function of CGFs in osteoinduction. The application of the atoxic RADA16 nanofiber scaffold hydrogel with CGFs can be a new therapeutic strategy for the treatment of alveolar bone loss and other problems that require bone regeneration.

Protocol for IPO11 deletion and re-expression in H460 lung cancer cells using CRISPR-Cas9 and plasmid transfection.

Exploring the essential role of Importin 11 (IPO11) in the nuclear translocation of its potential cargo proteins requires an efficient means of IPO11 deletion and re-expression. Here, we present a protocol for the generation of IPO11 deletion using CRISPR-Cas9 and re-expression using plasmid transfection in H460 non-small cell lung cancer cells. We describe steps for lentiviral transduction of H460 cells, single clone selection, and expansion and validation of cell colonies. We then detail plasmid transfection and validation of transfection efficiency. For complete details on the use and execution of this protocol, please refer to Zhang et al.1.

Adhesive Property of 3D-Printed PEEK Abutments: Effects of Surface Treatment and Temporary Crown Material on Shear Bond Strength.

Three-dimensionally printed polyetheretherketone (PEEK) materials are promising for fabricating customized dental abutments. This study aimed to investigate the adhesive property of a 3D-printed PEEK material. The effects of surface treatment and temporary crown materials on shear bond strength were evaluated. A total of 108 PEEK discs were 3D printed by fused-filament fabrication. Surface treatments, including sandblasting, abrasive paper grinding, and CO2 laser ablation, were applied to the PEEK discs, with the untreated specimens set as the control. Afterward, the surface topographies of each group were investigated by scanning electron microscopy (SEM, n = 1) and roughness measurements (n = 7). After preparing the bonding specimens with three temporary crown materials (Artificial teeth resin (ATR), 3M™ Filtek™ Supreme Flowable Restorative (FR), and Cool Temp NATURAL (CTN)), the shear bond strength was measured (n = 6), and the failure modes were analyzed by microscopy and SEM. The results showed that ATR exhibited a significantly higher shear bond strength compared to FR and CTN (p < 0.01), and the PEEK surfaces treated by sandblasting and abrasive paper grinding showed a statistically higher shear bond strength compared to the control (p < 0.05). For clinical application, the ATR material and subtractive surface treatments are recommended for 3D-printed PEEK abutments.

RPRM negatively regulates ATM levels through its nuclear translocation on irradiation mediated by CDK4/6 and IPO11.

How the ataxia telangiectasia mutated (ATM) protein kinase, a core protein in DNA damage response, is regulated at post-transcription level remains unclear. Here it is identified that protein Reprimo (RPRM) downregulates ATM protein levels, resulting in impaired DNA repair and enhanced cellular radiosensitivity. Mechanistically, although primarily localized in the cytoplasm, RPRM translocates to the nucleus shortly after induced by X-irradiation, interacts with ATM and promotes its nuclear export and proteasomal degradation. The RPRM nuclear translocation involves its phosphorylation at serine 98 mediated by cyclin-dependent kinases 4/6 (CDK4/6), and requires Importin-11 (IPO11). Of importance, IPO11-regulated RPRM nuclear import upon irradiation is essential for its regulation on ATM. Thus, RPRM overexpression and its phosphorylation inhibition sensitize cells to genotoxic agents such as irradiation, whereas RPRM deficiency significantly increases resistance to radiation-induced damage both in vitro and in vivo. These findings establish a crucial regulatory mechanism in which ATM is negatively modulated by RPRM.

TRIM56 impairs HBV infection and replication by inhibiting HBV core promoter activity.

Members of the tripartite motif (TRIM) protein family strongly induced by interferons (IFNs) are parts of the innate immune system with antiviral activity. However, it is still unclear which TRIMs could play important roles in hepatitis B virus (HBV) inhibition. Here, we identified that TRIM56 expression responded in IFN-treated HepG2-NTCP cells and HBV-infected liver tissues, which was a potent IFN-inducible inhibitor of HBV replication. Mechanistically, TRIM56 suppressed HBV replication via its Ring and C-terminal domain. C-terminal domain was essential for TRIM56 translocating from cytoplasm to nucleus during HBV infection. Further analysis revealed that TRIM56's Ring domain targeted IκBα for ubiquitination. This modification induced phosphorylation of p65, which subsequently inhibited HBV core promoter activity, resulting in the inhibition of HBV replication. The p65 was found to be necessary for NF-κB signal pathway to inhibit HBV replication. We verified our findings using HepG2-NTCP and primary human hepatocytes. Our findings reveal that TRIM56 is a critical antiviral immune effector and exerts an anti-HBV activity via NF-κB signal pathway, which is essential for inhibiting transcription of HBV covalently closed circular DNA.

Hepatitis B Virus Pregenomic RNA Reflecting Viral Replication in Distal Non-tumor Tissues as a Determinant of the Stemness and Recurrence of Hepatocellular Carcinoma.

Background: The existence of hepatic cancer stem cells (CSCs) contributes to chemotherapy resistance and cancer recurrence after treatment or surgery. However, very little is known about the hepatitis B virus (HBV) replication and its relationship with the stemness of hepatocellular carcinoma (HCC) in HBV-related HCC patients. Methods: We collected tumor tissues (T), matched adjacent non-tumor tissues (NT), and distal non-tumor tissues (FNT) from 55 HCC patients for analysis. Results: We found HBV DNA levels were higher in T samples than NT and FNT samples, but HBV pgRNA and total RNA expressed lower in T samples. HBV pgRNA and total RNA correlate to HBV DNA among the T, NT, and FNT samples. Further evidence for HBV replication in T samples was provided by HBV S, reverse transcriptase, and X genes sequencing, showing that HBV sequences and genotypes differed between T and matched NT and FNT samples. HBV pgRNA and total RNA showed more frequent significant correlations with CSC markers in NT samples in HBsAg-positive patients. The markers CD133 and OCT4 expressed higher in FNT samples, and HBV replication marker of pgRNA levels was significantly positively correlated to these two markers only in FNT samples. The detection of pgRNA and OCT4 in FNT was correlated to the recurrence of HCC in the resection of HCC patients. Analysis of HBV receptor, sodium taurocholate co-transporting polypeptide (NTCP), showed that NTCP was correlated negatively to CSC markers in T samples, except for the CD44. Conclusion: HBV replication may present in HCC with a weak transcriptomic signature. Moreover, the expression level of HBV pgRNA in distal non-tumor tissues is a sensitive marker for HBV replication and prognosis, which is associated with CSC-related markers especially with OCT4 in distal non-tumor tissues and recurrence of HCC in HBV-related HCC patients.

The enhancement role of Matrigel on HBV infection in HepG2-NTCP cells.

The hepatoma cell lines stably expressing sodium taurocholate cotransporting polypeptide (NTCP), the receptor of hepatitis B virus (HBV) infection, serve as important infection models for studying viral biology and drug discovery. However, the efficiency of infection greatly varies. In this study, we studied the effects and potential mechanisms of Matrigel® hESC-qualified (M-hq), a biological basement membrane matrix commonly used in cell culture, on promotion HBV in vitro infection in HepG2-NTCP cells. For the first time, our findings demonstrate that M-hq could enhance the infection efficiency of cell culture-derived HBV with no impact on the cell viability, the HBV transcription and response to antiviral treatments. The infection enhancement is reproducible and is suggested to occur at HBV attachment step. Our study suggests that this novel system is applicable for studying HBV biology and new drugs.

The Genotype (A to H) Dependent N-terminal Sequence of HBV Large Surface Protein Affects Viral Replication, Secretion and Infectivity.

Genetic variability has significant impacts on biological characteristics and pathogenicity of hepatitis B virus (HBV), in which the N-terminal sequence of the presurface 1 (preS1) region of HBV large surface protein (LHBs) displays genotype (GT) dependent genetic heterogeneity. However, the influence of this heterogeneity on its biological roles is largely unknown. By analyzing 6560 full-length genome sequences of GTA-GTH downloaded from HBVdb database, the preS1 N-terminal sequences were divided into four representative types, namely C-type (representative of GTA, GTB, and GTC), H-type (GTF and GTH), E-type (GTE and GTG), and D-type (GTD), respectively. We artificially substituted the preS1 N-termini of GTC and GTD plasmids or viral strains with each sequence of the four representative types. The roles of preS1 N-terminus on HBV replication, secretion and infectivity were investigated using HepG2 or HepG2-NTCP cells. In the transfection experiments, the results showed that the extracellular HBsAg levels and HBsAg secretion coefficients in D- and E-type strains were significantly higher than those in C- and H-type strains. D-type strain produced more extracellular HBV DNA than C-type strain. We further observed that D-, H-, and E-type strains increased the levels of intracellular replicative HBV DNAs, comparing with C-type strain. In the infection experiments, the levels of extracellular HBeAg, intracellular HBV total RNA and pgRNA/preC mRNA in D- and E-type strains were markedly higher than C and H-type ones. Our data suggest that the preS1 N-termini affect HBV replication, secretion and infectivity in a genotype dependent manner. The C- and H-type strains prefer to attenuate HBsAg secretion, while the strains of D- and E-type promoted infectivity. The existence and function of the intergenotypic shift of preS1 in naturally occurring recombination requires further investigation, as the data we acquired are mostly related to recombinant preS1 region between N-terminus of preS1 from genotypes A-H and the remaining preS1 portion of GTC or GTD.

A novel cell culture model reveals the viral interference during hepatitis B and C virus coinfection.

Coinfection of hepatitis B virus (HBV) and hepatitis C virus (HCV) may result in severe liver disease and frequent progression to cirrhosis and hepatocellular carcinoma. Clinical evidence suggests that HBV replication is suppressed by replicating HCV and often rebounds after treatment with drugs against HCV. Thus, a highly efficient cell culture system permissive for HBV/HCV would facilitate investigation on the interaction and pathogenesis after coinfection. Here we reported a robust HBV/HCV coinfection cell culture model by overexpressing human sodium-taurocholate cotransporting polypeptide (NTCP), CD81 and Mir122 into HepG2 cells and investigated interactions between HBV and HCV. In this system, HepG2-NTCP/CD81/Mir122 cells not only supported robust infection and replication of HBV and HCV, but also allowed HBV/HCV coinfection in the single cell level. Our result showed cells with replicating HBV still supported HCV infection. However, HBV replication was suppressed by HCV through the inhibition of HBV core promoter and S promoter II activity, and this inhibition was attenuated by the interferon alpha (IFNα) treatment, suggesting HCV influence on HBV at transcriptional level. Coinfection of HBV/HCV in this system did not block IFN stimulated genes expression. Inhibition of HCV by direct-acting antiviral drugs restored HBV replication and expression of viral genes. Conclusions: HepG2-NTCP/CD81/Mir122 fully supports HBV/HCV coinfection, replication and interaction. This novel cell model offers a platform to advance our understanding of the molecular details of the interaction, pathogenesis and outcomes of HBV/HCV coinfection.

Alpha-ketoglutarate ameliorates age-related osteoporosis via regulating histone methylations.

Age-related osteoporosis is characterized by the deterioration in bone volume and strength, partly due to the dysfunction of bone marrow mesenchymal stromal/stem cells (MSCs) during aging. Alpha-ketoglutarate (αKG) is an essential intermediate in the tricarboxylic acid (TCA) cycle. Studies have revealed that αKG extends the lifespan of worms and maintains the pluripotency of embryonic stem cells (ESCs). Here, we show that the administration of αKG increases the bone mass of aged mice, attenuates age-related bone loss, and accelerates bone regeneration of aged rodents. αKG ameliorates the senescence-associated (SA) phenotypes of bone marrow MSCs derived from aged mice, as well as promoting their proliferation, colony formation, migration, and osteogenic potential. Mechanistically, αKG decreases the accumulations of H3K9me3 and H3K27me3, and subsequently upregulates BMP signaling and Nanog expression. Collectively, our findings illuminate the role of αKG in rejuvenating MSCs and ameliorating age-related osteoporosis, with a promising therapeutic potential in age-related diseases.

The modulation of HBsAg level by sI126T is affected by additional amino acid substitutions in the S region of HBV.

The hepatitis B surface antigen (HBsAg) is a vital serum marker for hepatitis B virus (HBV) infection. Amino acid (AA) substitutions in small hepatitis B surface protein (SHBs) are known to affect HBsAg level. However, how the genetic backbones of SHBs sequences would affect the roles of a specific AA substitution on HBsAg level remains unclear. In this study, we found that sI126 had a very high substitution detection rate of 17.54% (40/228) in untreated chronic hepatitis B cohort with subgenotype C2 HBV infection. Among different substitution types at sI126, the sI126T (N = 28) was found to be associated with significantly lower serum HBsAg level. Clone sequencing revealed that sI126T-harboring SHBs sequences had varied genetic backbones with zero to nine additional AA substitutions. Thus, we constructed 24 HBsAg expression plasmids harboring sI126T without (plasmid 1, P1) or with (P2-P24) additional AA substitution(s) and studied them in the HepG2 cells. The HBsAg levels were determined by both ELISA and Western blot. In vitro experiments showed that P1 significantly reduced HBsAg level and its secretion (p < .05), however, P2-P24 showed various extracellular and intracellular HBsAg levels. No significant differences were detected among the HBsAg mRNA levels of nine representative mutant plasmids. Our findings suggest that the modulation of HBsAg level by sI126T is affected by additional AA substitution(s) in the S region of HBV. The effects of AA combination substitutions in SHBs sequences on HBsAg levels are worthwhile for more attentions in terms of HBV biology and its clinical application.

[Implant prosthesis design scheme for sophisticated congenital partial edentia].

Sophisticated congenital partial edentia are often accompanied by severe shortage of bone height and width due to the absence of permanent teeth; such condition will affect implant placement. This study aimed to display the different typical implant rehabilitation schemes we designed for sophisticated congenital partial edentia cases with severely atrophic alveolar bone.

Crude triterpenoid saponins from Anemone flaccida (Di Wu) exert anti-arthritic effects on type II collagen-induced arthritis in rats.

BACKGROUND: Anemone flaccida Fr . Schmidt (Ranunculaceae) (Di Wu in Chinese) is used to treat punch injury and rheumatoid arthritis (RA). However, the active compounds and underlying mechanism of action mediating the anti-arthritic effects of A. flaccida remain unclear. This study aims to evaluate the underlying action mechanism of A. flaccida crude triterpenoid saponins (AFS) on RA using a type II collagen (CII)-induced arthritis (CIA) rat model, and to assess the anti-inflammatory effects of the main active compounds of AFS, namely flaccidoside II, anhuienoside E, glycoside St-I4a, hemsgiganoside B, hederasaponin B, and 3-O-α-l-rhamnopyranosyl (1 â†’ 2)-ß-d-glucopyranosyl oleanolic acid 28-O-ß-d-glucopyranosyl (1 â†’ 6)-ß-d-glucopyranosyl ester. METHODS: Male Wistar rats (n = 50) were randomly separated into five groups (n = 10) and immunized by CII injection. AFS (200 or 400 mg/kg) and dexamethasone were orally administered for 30 days after establishing the model. The arthritis severity was assessed by paw volume using a plethysmometer. After 30 days of treatment, the right hind paws of the rats were obtained. Paw histology was analyzed by hematoxylin and eosin staining, and radiologic imaging was performed by micro-computed tomography. MTT assays were used to evaluate the cytotoxicity of AFS and its main compounds in RAW264.7 cells. Enzyme-linked immunosorbent assay kits were used to measure interleukin (IL)-6 and tumor necrosis factor (TNF)-α in serum and supernatants from AFS- and main AFS compound-treated RAW264.7 cells stimulated by lipopolysaccharide (LPS). RESULTS: Anemone flaccida crude triterpenoid saponins inhibited redness and swelling of the right hind paw in the CIA model. Radiological and histological examinations indicated that inflammatory responses were reduced by AFS treatment. Moreover, comparing with untreated rats, serum TNF-α (P = 0.0035 and P < 0.001) and IL-6 (P = 0.0058 and P = 0.0087) were lower in AFS-treated CIA rats at the dose of 200 and 400 mg/kg/day. AFS and its main compounds, including hederasaponin B, flaccidoside II, and hemsgiganoside B, significantly inhibited TNF-α (P = 0.0022, P = 0.013, P = 0.0015, and P = 0.016) and IL-6 (P = 0.0175, P < 0.001, P < 0.001, and P < 0.001) production in LPS-treated RAW264.7 cells, respectively. CONCLUSIONS: Anemone flaccida crude triterpenoid saponins and its main bioactive components, including hederasaponin B, flaccidoside II, and hemsgiganoside B, decreased pro-inflammatory cytokine levels in a CIA rat model and LPS-induced RAW264.7 cells.

Impact of targeted PPARγ disruption on bone remodeling.

Peroxisome proliferator-activated receptor gamma (PPARγ), known as the master regulator of adipogenesis, has been regarded as a promising target for new anti-osteoporosis therapy due to its role in regulating bone marrow mesenchymal stem/progenitor cell (BMSC) lineage commitment. However, the precise mechanism underlying PPARγ regulation of bone is not clear as a bone-specific PPARγ conditional knockout (cKO) study has not been conducted and evidence showed that deletion of PPARγ in other tissues also have profound effect on bone. In this study, we show that mice deficiency of PPARγ in cells expressing a 3.6 kb type I collagen promoter fragment (PPAR(fl/fl):Col3.6-Cre) exhibits a moderate, site-dependent bone mass phenotype. In vitro studies showed that adipogenesis is abolished completely and osteoblastogenesis increased significantly in both primary bone marrow culture and the BMSCs isolated from PPARγ cKO mice. Histology and histomorphometry studies revealed significant increases in the numbers of osteoblasts and surface in the PPARγ cKO mice. Finally, we found that neither the differentiation nor the function of osteoclasts was affected in the PPARγ cKO mice. Together, our studies indicate that PPARγ plays an important role in bone remodeling by increasing the abundance of osteoblasts for repair, but not during skeletal development.

Fabrication and bioactivity evaluation of porous anodised TiO2 films in vitro.

This study aims to find an optimal method for modifying the neck of dental implants for gingival attachment through in vitro investigations of the biological features of various anodised TiO2 films. The titanium sheets were divided into four groups: a control group and three test groups classified according to the anodisation voltage (Group 150 V, Group 180 V or Group 200 V).The surface microstructure and crystal structure were observed using scanning electron microscopy and X-ray diffraction. The protein adsorption ability, antibacterial activity and cell adhesion ability were tested to examine the biological properties of the materials in vitro. Microscopic grooves were observed in the control group, whereas the test groups contained numerous pores. Group 180 V and Group 200 V showed higher protein adsorption ability (p < 0.05), whereas Group 150 V and Group 180 V exhibited better antibacterial activity (p < 0.05). Higher cell concentrations of L929 were observed in Group 180V and Group 200 V than in the other two groups (p < 0.05), which indicated that the TiO2 films formed at 180 V promote protein adsorption and enhance fibroblast growth while inhibiting bacterial adhesion. These results indicate that anodisation positively affects the formation of a biological seal in the neck region of dental implants.

A study of force distribution of loading stresses on implant-bone interface on short implant length using 3-dimensional finite element analysis.

OBJECTIVE: The purpose of this study is to evaluate the biomechanics of short dental implants. STUDY DESIGN: Three-dimensional finite element analysis was used to simulate stress distribution of 8-mm implants with 6 different diameters in I to IV types of bone densities; meanwhile, axial and oblique loads were applied in this study. RESULTS: It was found that the maximum Von-Mises stress varied significantly when the diameter was within 3.3 mm and 5 mm, whereas the change of peak stress was not obvious when the diameter was within 5.5 mm to 7.1 mm. The peak stress on the implant-bone interface increased with the reduction of bone density. The stress in types I and II had similar distribution and the same was true for types III and IV. CONCLUSIONS: These results revealed that implants with larger diameter (<5.5 mm) and bone quality enhancement may be preferable to get better clinical effects. Prospective clinical studies are required to confirm this.

Clinical use of ridge-splitting combined with ridge expansion osteotomy, sandwich bone augmentation, and simultaneous implantation.

Our aim was to describe and evaluate the outcome of ridge-splitting and simultaneous implantation combined with ridge expansion osteotomy and sandwich-bone augmentation in the aesthetic zone. Thirty-one patients aged from 21-55 years who presented with narrow edentulous ridges (2.88∼5.08mm) were treated by ridge-splitting together with ridge expansion osteotomy and sandwich-bone augmentation to correct the osseous deficiency for simultaneous implantation. Bicon(®) implants were used. Calipers were used for biometric evaluation of the width of the ridge at both the first and second operations. Cone-beam computed tomography (CT, Morita, Kyodo, Japan) was used to assess the morphology of the ridge and the outcome of the operation. Forty-three implants were placed in the 31 patients selected, and none failed. At follow up all the implants functioned well and we saw no sign of gingival recession. Biometric evaluation at the surgical sites showed that the mean (SD) amount of augmentation of the ridge in the buccopalatal dimension was 2.8 (0.7) mm, p<0.01). For a narrow edentulous ridge in an aesthetic zone, ridge splitting together with ridge expansion osteotomy and sandwich-bone augmentation is a reliable technique.

Piezoelectric surgery in maxillary sinus floor elevation with hydraulic pressure for xenograft and simultaneous implant placement.

Because of the low bone quality in the posterior maxilla, edentulism in this area often results in a resorbed osseous structure and a pneumatized maxillary sinus, which makes dental implant surgery in the posterior maxilla a challenge. Two main surgical approaches are available for the sinus lift procedure: lateral and crestal. Improvement of the maxillary sinus floor elevation technique and increase in predictability are desirable. This article describes an innovative approach to maxillary sinus floor elevation with piezoelectric surgery and hydraulic pressure for xenograft and simultaneous implant placement in situations with insufficient residual alveolar bone.

Expression of cellular fibronectin mRNA in adult periodontitis and peri-implantitis: a real-time polymerase chain reaction study.

Cellular fibronectin (cFn) is a type of bioactive non-collagen glycoprotein regarded as the main substance used to maintain periodontal attachment. The content of cFn in some specific sites can reflect the progress of periodontitis or peri-implantitis. This study aims to evaluate the expression of cFn messenger RNA (mRNA) in tissues of adult periodontitis and peri-implantitis by real-time fluorescent quantitative polymerase chain reaction (PCR) and to determine its clinical significance. A total of 30 patients were divided into three groups of 10: healthy, adult periodontitis and peri-implantitis. Periodontal tissue biopsies (1 mm×1 mm×1 mm) from each patient were frozen in liquid nitrogen. Total RNA was extracted from these tissues, and the content, purity and integrity were detected. Specific primers were designed according to the sequence, and the mRNA expression levels of cellular fibronectin were detected by real-time PCR. The purity and integrity of the extracted total RNA were both high, and the specificity of amplified genes was very high with no other pollution. The mRNA expression of cFn in the adult periodontitis group (1.526±0.441) was lower than that in the healthy group (3.253±0.736). However, the mRNA expression of cFn in the peri-implantitis group (3.965±0.537) was significantly higher than that in the healthy group. The difference revealed that although both processes were destructive inflammatory reactions in the periodontium, the pathomechanisms were different and the variation started from the transcription level of the cFn gene.