Recombinant Mycobacterium bovis BCG is a promising platform to develop vaccines against Trypansoma cruzi infection

Chagas disease, caused by the hemoflagelate parasite Trypanosoma cruzi, is one of the most prevalent endemic parasitoses, affecting 7-8 million people. Due to the complexity of the infection, no vaccines are available at present. The extraordinary adjuvant capacity of bacille Calmette-Guérin (BCG) was explored in this work to develop a vaccine candidate to protect against T. cruzi infection using the recombinant BCG (rBCG) vaccine platform. Three antigens of the parasite corresponding to the N and C terminal fragments of the enzyme trans-sialidase (NT-TS and CT-TS, respectively) and a fragment of the cruzipain enzyme (CZf) were cloned into the vectors pUS997 and pUS2000 and transformed into the BCG Pasteur strain. In vaccinated mice, rBCG expressing NT-TS in pUS2000 plasmid provided the highest protection and the lowest parasitemia after challenging BALB/c mice with a 50% lethal dose of parasites. When mice vaccinated with pUS2000-NT-TS were challenged with a 100% lethal dose of parasite, high levels of protection were also obtained, together with a low degree of cardiac lesions 120 days after infection. In immunized mice with pUS2000-NT-TS/rBCG clone, the proliferation of CD4⁺ cells from splenocytes stimulated with the TS antigen was significant; this stimulation increased interferon (IFN)-γ and interleukin (IL)-17 within CD4⁺ T lymphocytes (LTCD4⁺ ) cells and IFN-γ and CD107 expression within LTCD8⁺ cells. Therefore, pUS2000-NT-TS/rBCG conferred high levels of protection, which correlated with an immune response orientated towards a T helper type 1 (Th1)/Th17 profile, together with an LTC-specific response, indicating that rBCG is a promising platform to develop vaccines against T. cruzi.

P4460microRNA-17-5p and microRNA-20a-5p downregulation by atorvastatin in Hepg2 cells: a new mechanism involved in the lipid-lowering therapy

Background

Hypercholesterolemia increases the risk of coronary artery disease and its pharmacological treatment has demonstrated, besides reducing cholesterol levels, a decrease in the incidence and mortality from coronary events. The treatment of hypercholesterolemia is mainly driven by using statins. However, the response to pharmacological therapy shows high inter-individual variability, resulting in a variable effect in both lipid lowering and risk reduction. Thus, a better understanding of lipid-lowering mechanism and response variability at molecular level is required. Previously, we demonstrated a deregulation of microRNA (miR) profile in HepG2 cells after atorvastatin treatment, including the downregulation of miR-17-5p and miR-20a-5p which potentially targets the LDL receptor gene (LDLR), suggesting that it might be involved in allowing the LDLR overexpression on the surface of hepatic cells to subsequently capture circulating LDL and to reach the expected lipid-lowering effect.

Purpose

To determine the role of miR-17-5p and miR-20a-5p on the regulation of LDLR gene expression in HepG2 cells.

Methods

Cells HepG2 were treated with atorvastatin 10μM for 24 hours. RNA extraction and enrichment of smallRNAs were performed. The gene expression of miR-17-5p, miR-20a-5p, miR-24-3p, miR-93-5p, miR-106a-5p and LDLR were evaluated. To evaluate the effect of miR-17-5p and miR-20a-5p on LDLR gene expression, both miRs were overexpressed or repressed by transfection of mimics or inhibitors respectively into HepG2 cells for 24, 48 and 72 Hours. The gene expression of LDLR was quantified by real time PCR using RPL27 gene as reference gene. The protein expression of LDLR and beta actin were evaluated using western blot and quantified using the ImageJ software.

Results

Our data showed that atorvastatin significantly repressed the expression of miR-17-5p (P<0.0001) and miR-20a-5p (P=0.0456) in HepG2 cells. In silico studies showed that miR-17-5p interact with the 3'-UTR region of the LDLR. Consistently, when miR-17-5p or miR-20a-5p were overexpressed by using mimics, we observed that gene and protein expression of LDLR decreased significantly (P<0.0001 and P<0.05 respectively). Consistently, when miR-17-5p or miR-20a-5p were repressed by the use inhibitors, we observed that the gene and protein expression of LDLR increases significantly (P<0.005).

Conclusions

In conclusion, we demonstrate that atorvastatin induces a significant down-regulation of the miR-17-5p and miR-20a-5p in HepG2 cells. The overexpression or repression regulate the gene and protein expression of LDLR.

Acknowledgement/Funding

FONDECYT N°3160567, FONDECYT N°1171765 and DIUFRO DI19-0094

Squamous cell carcinoma of gingiva and edentulous alveolar ridge: a clinicopathologic study

All oral squamous cell carcinomas were retrieved from the files of Temple University's Oral Pathology Laboratory from 1967 through 1994 for a clinicopathologic study of those occurring on the gingiva. A total of 1,193 cases had sufficient data for tabulation and statistical analysis, of which 300 (25%) arose on the gingiva or alveolar ridge. The largest number of these cases (211/300) occurred on the mandibular gingiva or alveolar ridge. The mean age of the patients was 66.66 years, with males accounting for 57% of cases. Many case comparison analyses of oral squamous cell carcinomas do not separate oral subsites or specifically address carcinoma of the gingiva. The results were compared with other published series and suggest that further studies are needed because of the wide range of reported figures on the incidence of gingival squamous cell carcinomas.

Pharmacokinetic comparison of tablet and suspension dosage forms of carbamazepine

The bioavailability of two preparations of carbamazepine--the tablet and a new syrup-was studied in 9 adult male volunteers by measuring saliva and serum levels. Peak time was significantly earlier and peak level significantly higher in serum for syrup as compared to tablet. Levels remained higher for syrup for 12 hr. Saliva was contaminated for up to 2 hr by syrup ingestion, possibly for a half hour by the tablet. Beyond that, saliva/serum ratios remained stable. Saliva level variation was too large for pharmacokinetic studies but acceptable for clinical purposes if sampling was long enough after the last dose.