Temporal Progression of Lesions in Guinea Pigs Infected With Lassa Virus

Lassa virus (LASV) infection causes an acute, multisystemic viral hemorrhagic fever that annually infects an estimated 100 000 to 300 000 persons in West Africa. This pathogenesis study evaluated the temporal progression of disease in guinea pigs following aerosol and subcutaneous inoculation of the Josiah strain of LASV as well as the usefulness of Strain 13 guinea pigs as an animal model for Lassa fever. After experimental infection, guinea pigs ( Cavia porcellus; n = 67) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and serum chemistry and hematologic changes. Guinea pigs developed viremia on day 5 to 6 postexposure (PE), with clinical signs appearing by day 7 to 8 PE. Complete blood counts revealed lymphopenia and thrombocytopenia. Gross pathologic findings included skin lesions and congested lungs. Histologic lesions consisted of cortical lymphoid depletion by day 6 to 7 PE with lymphohistiocytic interstitial pneumonia at 7 to 8 days PE. Scattered hepatocellular degeneration and cell death were also noted in the liver and, to a lesser extent, in other tissues including the haired skin, lung, heart, adrenal gland, lymph nodes, thymus, and spleen. The first cell types to demonstrate staining for viral antigen were fibroblastic reticular cells and macrophages/dendritic cells in the lymph nodes on day 5 to 6 PE. This study demonstrates similarities between Lassa viral disease in human infections and experimental guinea pig infection. These shared pathologic characteristics support the utility of guinea pigs as an additional animal model for vaccine and therapeutic development under the Food and Drug Administration's Animal Rule.

Label-free aptasensor for adenosine deaminase sensing based on fluorescence turn-on

A label-free and fluorescence turn-on aptamer biosensor has been developed for the detection of adenosine deaminase (ADA) activity with simplicity and selectivity. Adenosine aptamer will form a tight stem-loop structure upon binding with adenosine. In the absence of ADA, only a small quantity of picagreen intercalates into the stem section of aptamer, resulting in a low fluorescence of picagreen when excited at 490 nm. Interestingly, after the addition of ADA, adenosine is hydrolyzed to inosine, and the released aptamer forms double-stranded DNA (dsDNA) with its complementary single-stranded DNAc, followed by the intercalation of picagreen to dsDNA. When the solution is excited, picagreen emits strong green fluorescence. The increased fluorescence intensity of picagreen is dependent on the concentration of ADA. The detection limit of the ADA is determined to be 2 U L(-1), which is lower than ADA cutoff value (4 U L(-1)) in the clinical requirement and more sensitive than most of the reported methods. Compared to other previous ADA sensors, the assay is not only label-free but also a turn-on signal, and possesses properties of lower cost and simpler detection system. Furthermore, this label-free strategy is also applicable to the assay of other enzymes and screening of corresponding inhibitors.

Socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces

OBJECTIVE

To explore socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces.

METHODS

This study used data from 1,732 children living in Guangxi, Hubei, Jilin and Shanxi who participated in the Third National Oral Health Survey in 2005. Questionnaires were completed by parents to collect information on family socioeconomic position (parental education and household income) and children's dental behaviours (toothbrushing frequency, sugar intake frequency and last dental visit). Children were clinically examined for dental caries, which was reported using the dmft index. Socioeconomic inequalities in children's caries experience were assessed in negative binomial regression models.

RESULTS

There were significant gradients in children's dmft by household income. Children's dmft increased from 2.63 in the highest income group to 4.70 in the lowest income group. However, parental education was not significantly related to childhood dental caries.

CONCLUSION

Clear social gradients in caries experience of deciduous teeth were found by household income but not parental education.

Chinese SLE Treatment and Research group (CSTAR) registry: V. gender impact on Chinese patients with systemic lupus erythematosus

Introduction

Many studies have shown that differences were observed between male and female lupus patients. Although systemic lupus erythematosus (SLE) affects mostly females (female:male ratio 9:1), male SLE patients show higher mortality due to kidney and neurological disease. Currently there are limited epidemiological data concerning lupus in the Chinese population. As such, the Chinese SLE Treatment and Research group (CSTAR) developed the first online registry of Chinese lupus patients in 2009, and represents a multicenter observational study that attempts to describe and compile the major clinical characteristics of lupus in Chinese patients.

Objective

To investigate the effect of gender on the phenotypes of Chinese SLE patients.

Patients and methods

Data for 2104 SLE patients were prospectively collected and included in the CSTAR registry. Patients fulfilled the 1997 American College of Rheumatology (ACR) SLE classification criteria. We conducted a cross-sectional case-control study to analyze patient clinical and laboratory data at onset and at enrollment. SLE disease activity scores (SLEDAI) were also measured at enrollment.

Results

This study included 1914 women and 190 men. Males and females showed no differences in mean ages at onset, delay of diagnosis and disease duration. Males presented more frequently with fever ( p = 0.003), while musculoskeletal involvement ( p = 0.001) and cytopenia ( p = 0.017) was more common in females as the initial manifestation at onset of SLE. For manifestations at enrollment, males presented more frequently with fever ( p = 0.005), renal disease ( p = 0.019), vasculitis ( p = 0.032) and neuropsychiatric lupus ( p = 0.007). For cumulative manifestations at enrollment, males presented more frequently with discoid rash ( p < 0.001) and neuropsychiatric lupus ( p = 0.036), while less frequently with arthritis ( p = 0.011). However, the laboratory data showed no significant differences between the two groups at enrollment. Males also had higher SLEDAI scores at enrollment ( p = 0.002).

Conclusions

Renal disease, vasculitis and neuropsychiatric lupus are more common in male SLE patients with higher SLEDAI scores compared to female SLE patients in China.

Resveratrol regulates mitochondrial reactive oxygen species homeostasis through Sirt3 signaling pathway in human vascular endothelial cells

Mitochondrial reactive oxygen species (mtROS) homeostasis plays an essential role in preventing oxidative injury in endothelial cells, an initial step in atherogenesis. Resveratrol (RSV) possesses a variety of cardioprotective activities, however, little is known regarding the effects of RSV on mtROS homeostasis in endothelial cells. Sirt3 is a mitochondrial deacetylase, which plays a key role in mitochondrial bioenergetics and is closely associated with oxidative stress. The goal of the study is to investigate whether RSV could attenuate oxidative injury in endothelial cells via mtROS homeostasis regulation through Sirt3 signaling pathway. We found that pretreatment with RSV suppressed tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in human umbilical vein endothelial cells (HUVECs) by increasing cell viability, inhibiting cell apoptosis, repressing collapse of mitochondrial membrane potential and decreasing mtROS generation. Moreover, the enzymatic activities of isocitrate dehydrogenase 2 (IDH2), glutathione peroxidase (GSH-Px) and manganese superoxide dismutase (SOD2) as well as deacetylation of SOD2 were increased by RSV pretreatment, suggesting RSV notably enhanced mtROS scavenging in t-BHP-induced endothelial cells. Meanwhile, RSV remarkably reduced mtROS generation by promoting Sirt3 enrichment within the mitochondria and subsequent upregulation of forkhead box O3A (FoxO3A)-mediated mitochondria-encoded gene expression of ATP6, CO1, Cytb, ND2 and ND5, thereby leading to increased complex I activity and ATP synthesis. Furthermore, RSV activated the expressions of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and Sirt3, as well as estrogen-related receptor-α (ERRα)-dependent Sirt3 mRNA transcription, which were abolished in the presence of AMPK inhibitor and AMPK, PGC-1α or Sirt3 siRNA transfection, indicating the effects of RSV on mtROS homeostasis regulation were dependent on AMPK-PGC-1α-ERRα-Sirt3 signaling pathway. Our findings indicated a novel mechanism that RSV-attenuated oxidative injury in endothelial cells through the regulation of mtROS homeostasis, which, in part, was mediated through the activation of the Sirt3 signaling pathway.

Blocking autophagy enhanced cytotoxicity induced by recombinant human arginase in triple-negative breast cancer cells

Depletion of arginine by recombinant human arginase (rhArg) has proven to be an effective cancer therapeutic approach for a variety of malignant tumors. Triple-negative breast cancers (TNBCs) lack of specific therapeutic targets, resulting in poor prognosis and limited therapeutic efficacy. To explore new therapeutic approaches for TNBC we studied the cytotoxicity of rhArg in five TNBC cells. We found that rhArg could inhibit cell growth in these five TNBC cells. Intriguingly, accumulation of autophagosomes and autophagic flux was observed in rhArg-treated MDA-MB-231 cells. Inhibition of autophagy by chloroquine (CQ), 3-methyladenine (3-MA) and siRNA targeting Beclin1 significantly enhanced rhArg-induced cytotoxic effect, indicating the cytoprotective role of autophagy in rhArg-induced cell death. In addition, N-acetyl-l-cysteine (NAC), a common antioxidant, blocked autophagy induced by rhArg, suggesting that reactive oxygen species (ROS) had an essential role in the cytotoxicity of rhArg. This study provides new insights into the molecular mechanism of autophagy involved in rhArg-induced cytotoxicity in TNBC cells. Meanwhile, our results revealed that rhArg, either alone or in combination with autophagic inhibitors, might be a potential novel therapy for the treatment of TNBC.

TRAIL-expressing gingival-derived mesenchymal stem cells inhibit tumorigenesis of tongue squamous cell carcinoma

Recent research has verified that mesenchymal stromal/stem cells (MSCs) derived from bone marrow or adipose tissues can migrate toward a variety of tumors. In this study, we explored whether human gingival-derived MSCs (G-MSCs) can migrate toward tongue squamous cell carcinoma (TSCC) and evaluated the antitumor effect of engineered G-MSCs in expressing and delivering the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). An in vitro cell migration assay with Transwell plates showed that human G-MSCs can migrate toward TSCC cell lines (Tca8113 and Cal27). Then, human G-MSCs, as a type of cell-based vehicle, were transduced with full-length TRAIL and enhanced green fluorescent protein reporter genes by the lentivirus (LV) system (G-MSCs with full-length TRAIL; G-MSCFLT). Tca8113 and Cal27 were co-cultured with G-MSCFLT, respectively, to evaluate the function of G-MSCFLT on tumor cells in vitro. This resulted in G-MSCFLT's inducing a great number of tumor cell necrosis and apoptosis. Meanwhile, in vivo antitumor assays were performed by administering G-MSCFLT to nude mice locally and systematically (mixed injection with tumor cells and tail vein injection). This showed that G-MSCFLT can reduce or even inhibit TSCC growth regardless of the method of administration, especially when the mixed injection of tumor cells and G-MSCFLT was at a ratio of 1:1, which showed no tumor formation. Furthermore, this verified that G-MSCFLT migrated toward TSCC in quantity. These data emphasize the effectiveness of G-MSCs as a vehicle for cell-based gene therapy and the antitumor activity of TRAIL-expressing G-MSCs.

Clinical and laboratory characteristics of systemic sclerosis patients with pulmonary arterial hypertension in China

OBJECTIVES

Pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality, especially in systemic sclerosis (SSc). Since there was no published study regarding PAH in the Chinese SSc population, we aimed to describe a cohort to provide some data for early diagnosis.

METHODS

We evaluated 236 systemic sclerosis patients prospectively registered in the EUSTAR (European League Against Rheumatism Scleroderma Trial and Research Group) database from the Peking Union Medical College Hospital from 2009 to 2012. Among them, 33 individuals received right heart catheterisations (RHC) while the remaining patients were grouped by echocardiographic data. These patients were classified into two groups, PAH and non-PAH group. Their clinical and laboratory features were statistically analysed to identify possible risk factors for PAH in Chinese SSc population.

RESULTS

The possible prevalence of PAH in SSc patients was approximately 11% in our study. Digital ulcers (52.0% vs. 31.2%), telangiectasias (64.0% vs. 37.6%) and gastroesophageal reflux disease (GERD) (60.0% vs. 36.2%) were more common in SSc patients with PAH. Some laboratory results were also proved to be significantly correlated with it. Logistic regression analysis showed that telangiectasias (OR=2.888, 95% CI=1.176-7.093), presence of GERD (OR=2.592, 95% CI=1.067-6.296), anti-RNP positivity (OR=24.384, 95% CI=1.978-36.651), IgA level elevation (OR=8.745, 95% CI 4.838-122.896) and FVC/TLCO ratio (OR=97.067, 95% CI 12.475-755.271) were associated with an increased odds for PAH in SSc patients.

CONCLUSIONS

This study described possible predictors of PAH in Chinese SSc population, which have been supported by similar studies in other ethnic groups.

Could pulmonary arterial hypertension be an active index of systemic lupus erythematosus? A successful case of SLE-PAH cured by methylprednisolone pulse therapy

A 35-year-old female patient was diagnosed with pulmonary arterial hypertension (PAH) by right heart catheterization (RHC) in the 3rd month of systemic lupus erythematosus (SLE) duration with high disease activity. Through methylprednisolone pulse therapy, she got total recovery from PAH proven by repeat catheterization and follow-ups. This is the first simultaneously diagnosed, totally recovered, gold standard-proved SLE-PAH case ever reported in the literature. We would like to share this successful case, and at the same time, we want to highlight the relationship between presentation of PAH and active disease manifestations of SLE patients, and to discuss how immune suppressive treatment could benefit this subset of patients.

L-malate enhances the gene expression of carried proteins and antioxidant enzymes in liver of aged rats

Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. To investigate the antioxidant mechanism of L-malate in the mitochondria, we analyzed the change in gene expression of two malate-aspartate shuttle (MAS)-related carried proteins (AGC, aspartate/glutamate carrier and OMC, oxoglutarate/malate carrier) in the inner mitochondrial membrane, and three antioxidant enzymes (CAT, SOD, and GSH-Px) in the mitochondria. The changes in gene expression of these proteins and enzymes were examined by real-time RT-PCR in the heart and liver of aged rats treated with L-malate. L-malate was orally administered in rats continuously for 30 days using a feeding atraumatic needle. We found that the gene expression of OMC and GSH-Px mRNA in the liver increased by 39 % and 38 %, respectively, in the 0.630 g/kg L-malate treatment group than that in the control group. The expression levels of SOD mRNA in the liver increased by 39 %, 56 %, and 78 % in the 0.105, 0.210, and 0.630 g/kg L-malate treatment groups, respectively. No difference were observed in the expression levels of AGC, OMC, CAT, SOD, and GSH-Px mRNAs in the heart of rats between the L-malate treatment and control groups. These results predicted that L-malate may increase the antioxidant capacity of mitochondria by enhancing the expression of mRNAs involved in the MAS and the antioxidant enzymes.

Involvement of NLRP3 inflammasome in rituximab-induced interstitial lung disease: a case report

WHAT IS KNOWN AND OBJECTIVE

Rituximab is a chimeric anti-CD20 IgG1 monoclonal antibody for the treatment of various forms of lymphoma and haematological autoimmune diseases. Interstitial lung disease is a rare but lethal pulmonary toxicity of rituximab. Nod-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is a molecular platform activated upon signs of cellular 'danger' to trigger the maturation of pro-inflammatory cytokines. We report the first case of rituximab-induced interstitial lung disease (R-ILD) with NLRP3 inflammasome activation in the lung.

CASE SUMMARY

A 30-year-old male patient diagnosed with idiopathic thrombocytopenic purpura (ITP) was treated with four cycles of rituximab in one month. Three weeks after last rituximab administration, he developed progressive dyspnoea associated with respiratory failure, which was diagnosed as R-ILD. The patient showed a good response to steroid treatment, and lung biopsy was performed 5 days after the treatment. Immunohistopathological studies of lung specimens showed high expressions of inflammasome components NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase-1 in lung interstitium with a heavy infiltration of CD19-positive cells. The levels of inflammasome-related cytokines IL-1β and IL-18 in the serum were declined during the therapy.

WHAT IS NEW AND CONCLUSIONS

This is the first report confirmed the role of NLRP3 inflammasome in pulmonary toxicity of rituximab. Inhibited activation of NLRP3 inflammasome in lung by steroid treatment could reverse R-ILD and block subsequent lung fibrosis. This result could open a new sight into the pathogenesis and provide a new target for the treatment of R-ILD.