A putative TetR regulator is involved in nitric oxide stress resistance in Porphyromonas gingivalis

To survive in the periodontal pocket, Porphyromonas gingivalis, the main causative agent of periodontal disease, must overcome oxidative and nitric oxide (NO) stress. Previously, we reported that, in the presence of NO comparable to stress conditions, the transcriptome of P. gingivalis was differentially expressed, and genes belonging to the PG1178-81 cluster were significantly upregulated. To further evaluate their role(s) in NO stress resistance, these genes were inactivated by allelic exchange mutagenesis. Isogenic mutants P. gingivalis FLL460 (ΔPG1181::ermF) and FLL461 (ΔPG1178-81::ermF) were black-pigmented, with gingipain and hemolytic activities comparable to that of the wild-type strain. Whereas the recovery of these isogenic mutants from NO stress was comparable to the wild-type, there was increased sensitivity to hydrogen peroxide-induced stress. RNA-Seq analysis under conditions of NO stress showed that approximately 5 and 8% of the genome was modulated in P. gingivalis FLL460 and FLL461, respectively. The PG1178-81 gene cluster was shown to be part of the same transcriptional unit and is inducible in response to NO stress. In the presence of NO, PG1181, a putative transcriptional regulator, was shown to bind to its own promoter region and that of several other NO responsive genes including PG0214 an extracytoplasmic function σ factor, PG0893 and PG1236. Taken together, the data suggest that PG1181 is a NO responsive transcriptional regulator that may play an important role in the NO stress resistance regulatory network in P. gingivalis.

Studies of the extracytoplasmic function sigma factor PG0162 in Porphyromonas gingivalis

PG0162, annotated as an extracytoplasmic function (ECF) sigma factor in Porphyromonas gingivalis, is composed of 193 amino acids. As previously reported, the PG0162-deficient mutant, P. gingivalis FLL350 showed significant reduction in gingipain activity compared with the parental strain. Because this ECF sigma factor could be involved in the virulence regulation in P. gingivalis, its genetic properties were further characterized. A 5'-RACE analysis showed that the start of transcription of the PG0162 gene occurred from a guanine (G) residue 69 nucleotides upstream of the ATG translation initiation codon. The function of PG0162 as a sigma factor was confirmed in a run-off in vitro transcription assay using the purified rPG0162 and RNAP core enzyme from Escherichia coli with the PG0162 promoter as template. As an appropriate PG0162 inducing environmental signal is unknown, a strain overexpressing the PG0162 gene designated P. gingivalis FLL391 was created. Compared with the wild-type strain, transcriptome analysis of P. gingivalis FLL391 showed that approximately 24% of the genome displayed altered gene expression (260 upregulated genes; 286 downregulated genes). Two other ECF sigma factors (PG0985 and PG1660) were upregulated more than two-fold. The autoregulation of PG0162 was confirmed with the binding of the rPG0162 protein to the PG0162 promoter in electrophoretic mobility shift assay. In addition, the rPG0162 protein also showed the ability to bind to the promoter region of two genes (PG0521 and PG1167) that were most upregulated in P. gingivalis FLL391. Taken together, our data suggest that PG0162 is a sigma factor that may play an important role in the virulence regulatory network in P. gingivalis.

The roles of RgpB and Kgp in late onset gingipain activity in the vimA-defective mutant of Porphyromonas gingivalis W83

Previous studies have shown that VimA, an acetyltransferase, can modulate gingipain biogenesis in Porphyromonas gingivalis. Inactivation of the vimA gene resulted in isogenic mutants that showed a late onset of gingipain activity that only occurred during the stationary growth phase. To further elucidate the role and contribution of the gingipains in this VimA-dependent process, isogenic mutants defective in the gingipain genes in the vimA-deficient genetic background were evaluated. In contrast with the wild-type strain, RgpB and Kgp gingipain activities were absent in exponential phase in the ∆rgpA::tetQ-vimA::ermF mutant. However, these activities increased to 31 and 53%, respectively, of that of the wild-type during stationary phase. In the ∆rgpA::cat-∆kgp::tetQ-vimA::ermF mutant, the RgpB protein was observed in the extracellular fraction but no activity was present even at the stationary growth phase. There was no gingipain activity observed in the ∆rgpB::cat-∆kgp::tetQ-vimA::ermF mutant whereas Kgp activity in ∆rgpA::cat-∆rgpB::tetQ-vimA::ermF mutant was 24% of the wild-type at late stationary phase. In contrast to RgpA, the glycosylation profile of the RgpB catalytic domain from both W83 and P. gingivalis FLL92 (vimA::ermF) showed similarity. Taken together, the results suggest multiple gingipain activation pathways in P. gingivalis. Whereas the maturation pathways for RgpA and RgpB are different, the late-onset gingipain activity in the vimA-defective mutant was due to activation/maturation of RgpB and Kgp. Moreover, unlike RgpA, which is VimA-dependent, the maturation/activation pathways for RgpB and Kgp are interdependent in the absence VimA.

[Assessment of quality of life after multiple arthroplasty]

OBJECTIVE

To evaluate the effectiveness of conducting multiple arthroplasty to treat multiple joints disease in terms of quality of life (QOL) and function improvement.

METHODS

We compared our results with the reported results of single and dual arthroplasty to see if there is any improvement in QOL, functional scores or complications. In this study, 13 patients admitted to Department of Adult Reconstructive Surgery, Beijing Jishuitan hospital from 2005 to 2009 were included. Questionnaires SF-36 were used to evaluate the QOL. Harris hip score, American Knee Society Score (KSS) were used to evaluate the joint function. The patients were evaluated before surgery to the latest follow up.

RESULTS

SF-36 has changed as follow: physical function 4.17 ± 14.43 → 65.83 ± 24.76, role physical 25.00 ± 26.11 → 60.42 ± 45.8, bodily pain 23.83 ± 21.41 → 76.88 ± 20.89, general health 53.33 ± 33.87 → 76.67 ± 14.67, vitality 50.42 ± 17.25 → 71.67 ± 16.28, social functioning 29.17 ± 33.50 → 73.96 ± 33.90, role emotional 22.08 ± 35.61 → 77.77 ± 41.03, mental health 53.33 ± 25.70 → 82.67 ± 14.41, which indicated that they all improved greatly after the surgery (P < 0.05). Harris score increased from 37.68 ± 14.71 before the surgery to 83.36 ± 13.54 after the surgery. KSS has also showed sharp improvement (P < 0.001) in both clinical score (42.52 ± 23.83 → 77.74 ± 20.67) and function score (-2.61 ± 22.56 → 65.65 ± 30.76).

CONCLUSION

Multiple arthroplasty is one of the most effective methods which can markedly improve the quality of life in patients with multiple joints disease. But complications are common and joint functions are relatively poor.

Metabolome variations in the Porphyromonas gingivalis vimA mutant during hydrogen peroxide-induced oxidative stress

The adaptability and survival of Porphyromonas gingivalis in the oxidative microenvironment of the periodontal pocket are indispensable for survival and virulence, and are modulated by multiple systems. Among the various genes involved in P. gingivalis oxidative stress resistance, vimA gene is a part of the 6.15-kb locus. To elucidate the role of a P. gingivalis vimA-defective mutant in oxidative stress resistance, we used a global approach to assess the transcriptional profile, to study the unique metabolome variations affecting survival and virulence in an environment typical of the periodontal pocket. A multilayered protection strategy against oxidative stress was noted in P. gingivalis FLL92 with upregulation of detoxifying genes. The duration of oxidative stress was shown to differentially modulate transcription with 94 (87%) genes upregulated twofold during 10 min and 55 (83.3%) in 15 min. Most of the upregulated genes (55%), fell in the hypothetical/unknown/unassigned functional class. Metabolome variation showed reduction in fumarate and formaldehyde, hence resorting to alternative energy generation and maintenance of a reduced metabolic state. There was upregulation of transposases, genes encoding for the metal ion binding protein transport and secretion system.

Role of cathepsin B in regulating migration and invasion of fibroblast-like synoviocytes into inflamed tissue from patients with rheumatoid arthritis

Cathepsin B (CB), an important proteinase that participates in joint destruction in rheumatoid arthritis (RA), exhibits higher expression in fibroblast-like synoviocyte (FLS) of abnormal proliferative synovial tissues. Whether and how it affects the biological behaviours of RA-FLS, such as migration and invasion, are poorly understood. In the present study, CB expression in synovial tissues of patients with RA and ostearthritis (OA) were measured by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC), respectively. Stable depletion of endogenous CB was achieved by small interfering RNA (siRNA) transfection, and decrease of CB activity was acquired by using its specific inhibitor (CA074Me). The effects of CA074Me and RNA interference (RNAi) treatments on proliferation, migration, invasion, matrix metalloproteinase (MMP)-2/-9 expression, focal adhesion kinase (FAK) activation, and mitogen-activated protein kinases (MAPKs) phosphorylation of FLS were analysed. In RA synovial tissues, CB was expressed at elevated levels compared with OA synovial tissues. CA074Me could inhibit invasion of FLS obtained from RA patients in an ex-vivo invasion model. CA074Me and siRNA treatments suppressed the migration and invasion of FLS, reduced the activity, expression and mRNA level of MMP-2, restrained the activation of FAK and reduced the expression of F-actin. Moreover, CA074Me decreased the phosphorylation of P38 MAPK and c-Jun N-terminal kinase (JNK) in FLS, while siCB treatment reduced the phosphorylation of P38 but not JNK. CB substantially contributes to the invasive phenotype of FLS that leads to joint destruction in RA. This proteinase may show promise as a therapeutic target in inflammatory arthritis.

Clinical characteristics and therapy exploration of active human cytomegalovirus infection in 105 lupus patients

Systemic lupus erythematosus (SLE) has protean clinical manifestations of varying severity over the course of its onset, exacerbation, remission and flare that could often pose significant challenges for clinicians in their decision making as to whether to treat aggressively or to look for concurrent conditions such as infection with opportunistic pathogens. Human cytomegalovirus (HCMV) is one of those pathogens and is frequently encountered in our daily management of lupus patients. To investigate the clinical characteristics and therapeutic options of active HCMV infection in patients with SLE, we retrospectively reviewed clinical data of 105 inpatients in our department of Rheumatology and Clinical Immunology of Peking Union Medical College Hospital (PUMCH) diagnosed with both SLE and active HCMV infection from January 2006 to January 2012. Three groups were designated that included 42 cases of HCMV triggering SLE, 31 cases of HCMV exacerbating SLE, and 32 cases of HCMV mimicking SLE flare based on the relationship of HCMV infection and SLE. 1) Hematocytopenia (81%), fever (73.3%) and liver dysfunction (54.3%) were the most common clinical manifestations. The differences among the three groups with regard to butterfly erythema, cutaneous vasculitis, arthritis, serositis, central nervous system involvement and renal involvement were statistically significant (p < 0.05). 2) Positive rate of HCMV-pp65, compared with HCMV-IgM and HCMV-DNA, was the highest (84.9%) in patients with SLE and active HCMV infection. 3) Following 14-21 days of inductive treatment with ganciclovir, a total of 26 out of 56 patients were still positive with HCMV-IgM (nine of 19, 47.6%) and pp65 (17/37, 45.9%). Among them, seven cases suffered HCMV relapses in three months with six cases of sustained HCMV-pp65 antigenemia. In conclusion, hematocytopenia, fever and liver dysfunction should remind us to consider HCMV infection. Butterfly erythema, cutaneous vasculitis, arthritis, serositis, central nervous system involvement and renal lesion were relatively characteristic symptoms of lupus activity. HCMV-pp65 is a sensitive indicator to guide antiviral therapy. Induction therapy using ganciclovir with a duration of 14∼21 days is not sufficient, and continued HCMV-pp65 positivity may require prolonged antiviral treatment in lupus patients.

Survey and analysis on birth quality influence factors of 300 cases of newborns

PURPOSE

Little research has been conducted to specifically identify the correlations of birth quality influence factors of newborns and hemoglobin of gravidae and puerperal with birth weight of newborns. To investigate the correlations of birth quality influence factors of newborns and hemoglobin of gravidae and puerperal with birth weight of newborns in order to provide a scientific basis for promoting health ofgravidae and their newborns.

MATERIALS AND METHODS

Three hundred cases of gravidae and puerpera treated in the present hospital were randomly selected, and questionnaire survey method was used to survey their basic situations. Also, hemoglobin values in different pregnancy stages were detected. According to birth weight of newborns, gravidae were divided into several groups to compare antepartum hemoglobin levels of various groups of gravidae. In addition, logistic regression analysis was carried out for birth quality influence factors of newborns.

RESULTS

Logistic regression analysis result showed that birth quality influence factors of newborns included age, nutrition situation and pregnancy healthcare education of gravidae and puerpera. In addition, birth weight of newborns was positively related to antepartum hemoglobin level of gravidae (r = 0.746, p < 0.01).

CONCLUSIONS

It was feasible for promoting smooth delivery of gravidae and puerpera, reducing incidence rate of mother and baby complications and effectively enhancing health situations of newborns to strengthen health monitoring of gravidae and conduct health education intervention.

VimA-dependent modulation of the secretome in Porphyromonas gingivalis

The VimA protein of Porphyromonas gingivalis is a multifunctional protein involved in cell surface biogenesis. To further determine if its acetyl coenzyme A (acetyl-CoA) transfer and putative sorting functions can affect the secretome, its role in peptidoglycan biogenesis and effects on the extracellular proteins of P. gingivalis FLL92, a vimA-defective mutant, were evaluated. There were structural and compositional differences in the peptidoglycan of P. gingivalis FLL92 compared with the wild-type strain. Sixty-eight proteins were present only in the extracellular fraction of FLL92. Fifteen proteins present in the extracellular fraction of the parent strain were missing in the vimA-defective mutant. These proteins had protein sorting characteristics that included a C-terminal motif with a common consensus Gly-Gly-CTERM pattern and a polar tail consisting of aromatic amino acid residues. These observations suggest that the VimA protein is likely involved in peptidoglycan synthesis, and corroborates our previous report, which suggests a role in protein sorting.

Colitogenic role of tumour necrosis factor (TNF) receptors in trinitrobenzene sulphonic acid colitis: TNF-R1 ablation does not affect systemic inflammatory response

Tumour necrosis factor (TNF)-α plays a critical role in the pathogenesis of T helper type 1-mediated colitis such as Crohn's disease. However, the roles of its two receptors in mediating pathology remain largely unknown. In this study, trinitrobenzene sulphonic acid (TNBS) was used to induce colitis in TNF-receptor single or double knock-out (DKO) BALB/c mice and in wild-type counterparts. TNF-R1(-/-) mice had significantly less weight loss, reduced mortality, colon shortening and oedema, colon histological damage and lower levels of colon myeloperoxidase compared with wild-type (WT) BALB/c mice. A similar manifestation was also observed in TNF-R2(-/-) and TNF-R1(-/-) TNF-R2(-/-) (TNF-R DKO) mice. Strikingly, systemic inflammatory response (including splenomegaly and monocyte expansion) was found in WT and TNF-R1(-/-) mice after TNBS, instead of TNF-R2(-/-) and TNF-R DKO mice. Attenuated pathology of colitis in TNF-R1(-/-) or TNF-R2(-/-) mice correlated with lower amounts of interleukin (IL)-6, IL-1β, monocyte chemotactic protein (MCP)-1, IL-12p70 and interferon (IFN)-γ production in the colons. Importantly, ablation of TNF-R1 or TNF-R2 reduced the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL)-positive apoptotic epithelial cells in the affected colons compared with WT TNBS-instilled controls, which might be due to the heightened ratio of Bcl-2/Bax and reduced activity of nuclear factor (NF)-κB. These findings suggest that either TNF-R1 or TNF-R2 plays a pathogenic role in the pathology of colitis and TNF signalling via TNF-R1 or TNF-R2 alone is not sufficient for inducing mucosal damage.

Abrogation of mitochondrial transcription in smooth muscle cells impairs smooth muscle contractility and vascular tone

BACKGROUND

Smooth muscle cells (SMC) constitute the major contractile cell population of blood vessels and inner organs. SMC contraction depends on energy provided by adenosine triphosphate (ATP) catabolism, which can be generated through oxidative phosphorylation in mitochondria or by anaerobic glycolysis. Mitochondrial activity may also modulate smooth muscle tone by biotransformation of vasoactive mediators. Here, we study the role of mitochondrial DNA gene expression for vascular function in vivo.

METHODS

Since loss of functional mitochondria in SMC may not be compatible with normal development, we generated mice with inducible SMC-specific abrogation of the mitochondrial transcription factor A (Tfam). Deletion of this gene leads to dysfunctional mitochondria and prevents aerobic ATP production in affected cells.

RESULTS

Invasive blood pressure monitoring in live animals demonstrated that SMC specific Tfam deletion results in lower blood pressure and a defective blood-pressure response to stress, changes that were not compensated by increased heart rate. The contractility to agonists was reduced in arterial and gastric fundus strips from Tfam-deficient mice. Endothelium-dependent relaxation of arterial strips in response to ACh was also blunted.

CONCLUSION

Our data show that mitochondrial function is needed for normal gastric contraction, vascular tone, and maintenance of normal blood pressure.