Peptide L13S Derived from the BRN2 POU Domain Reduces Metastasis In Vivo and Inhibits Cell Migration and Invasion In Vitro.

BACKGROUND/AIM: The Brain-Specific Homeobox/POU Domain Protein 2 (BRN2) transcription factor supports melanoma progression by regulating the expression of several genes involved in cell migration and invasion. We hypothesized that a peptide designed based on the POU domain of BRN2 could block the BRN2 transcription activity and, consequently, reduce metastasis. MATERIALS AND METHODS: Cell viability was accessed by Trypan Blue exclusion dye assay and xCelligence platform. Wound-healing scratch assay and transwell invasion with matrigel membrane assay were performed to analyze cell migration and invasion. The internalization mechanism of the L13S peptide was investigated using confocal microscopy and wound-healing scratch assay. The impact of L13S on cell protein expression was analyzed through western blotting. In vivo assays were conducted to evaluate the protective effect and toxicity of L13S in a metastatic model using murine melanoma cells. RESULTS: Here, we show that the peptide named L13S can inhibit the migration and invasion of murine melanoma cells (B16F10-Nex2) as well as the migration of human melanoma cells (SK-MEL-25 and A375) by regulating the expression of proteins involved in motility. Mechanistically, we found that L13S is internalized by murine melanoma cells via macropinocytosis and binds actin filaments and nuclei. More importantly, in vivo studies indicated that the peptide was able to significantly inhibit lung metastasis in syngeneic models without off-target effects and with virtually no cytotoxicity toward normal organs. CONCLUSION: L13S peptide is a strong candidate for further development as an anticancer agent for the treatment of melanoma metastasis.

A Systematic Review of LINE-1 Methylation Profile in Psychiatric Disorders.

Introduction: Long interspersed nuclear elements (LINEs) are endogenous retrotransposable elements. A few studies have linked the methylation pattern of LINE-1 to different mental disorders (e.g., post-traumatic stress disorder [PTSD], autism spectrum disorder [ASD], panic disorder [PD]). We sought to unify the existing knowledge in the field and provide a better understanding of the association between mental disorders and LINE-1 methylation. Methods: A systematic review was executed with 12 eligible articles according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: For psychotic disorders, PTSD, ASD, and PD, lower LINE-1 methylation levels were detected, whereas for mood disorders, the findings are controversial. The studies were conducted with subjects aged 18-80 years. Peripheral blood samples were utilized in 7/12 articles. Conclusion: Although most studies have shown that LINE-1 hypomethylation was associated with mental disorders, there were still some divergences (i.e., hypermethylation associated with mental disorders). These studies suggest that LINE-1 methylation may be an important factor related to the development of mental disorders and highlight the need to better comprehend the biological mechanisms underlying the role of LINE-1 in mental disorders pathophysiology.

Respiratory syncytial virus: viral load, viral decay, and disease progression in children with bronchiolitis.

Acute viral bronchiolitis is the major cause of hospital admissions in children under 2 years of age, and respiratory syncytial virus (RSV) can be responsible for up to 80% of these infections. We aimed to describe RSV dynamics among hospitalized children with bronchiolitis. Upper respiratory samples of 101 hospitalized patients were collected and submitted to RSV detection by a quantitative real-time RT-PCR to assess viral load (Log10 RNA copies/mL). Seventy-two patients were positive for RSV infection, of which 38 (52.7%) could be followed up until RSV was no longer detected. The first RSV RT-qPCR was carried out on average on the 5th day of symptom onset. Thirty-six patients (94.7%) were still shedding RSV after 7 days, and 9 (23.6%) after 14 days of symptoms onset. Only 2 patients (5.2%) were still shedding RSV after 21 days. Only 7 of the followed patients (18.9%) were submitted to intubation. There was no difference between the viral load of the first collected sample and the viral persistence of patients with comorbidities, who needed intensive care unit and who needed intubation. These data could help understand RSV dynamics and future studies and treatments to come.

Hepatitis E virus infection among patients with altered levels of alanine aminotransferase.

Hepatitis E virus (HEV) affects 20 million people worldwide, with 3.3 million cases and 56,000 deaths. The transmission is mainly by the fecal-oral route. Several studies have reported increased alanine aminotransferase (ALT) levels in association with viral hepatitis. This study evaluated the diagnosis of HEV infection among patients attending the emergency room (ER) of Hospital Beneficência Portuguesa (HBP) and Hospital São Paulo (HSP) in São Paulo, Brazil increased ALT levels (≥ 200 IU/L). From October 2018 to July 2019, 400 sera samples were collected from patients treated at the ER of HBP (n=200) and HSP (n=200). All samples were screened for HEV by RT-qPCR. 200 samples from HSP were tested for IgM of anti-Hepatitis A (HAV) and B (HBV) viruses, and total antibodies of Hepatitis C virus (HCV). Ninety samples (45 from each hospital), were tested for anti-HEV IgM antibodies. Patients aged under 1 to 91 years (mean = 46.29 ± 24.17, median = 48). ALT levels varied from 200 to 8,974 IU/l. 16 patients (4%) turned out positive for HEV by RT-qPCR (ALT levels = 299 to 698 IU/L). Of the 200 HSP patients, 18 (9%) were anti-HAV IgM reactive, 9 (4.5%) for anti-HBV IgM, and 7 (3.5%) for anti-HCV antibodies (ALT levels = 833 to 1918 IU/L). Two of 90 BPH patients (2.22%) were anti-HEV IgM reactive (ALT levels = 1502 to 3831 IU/L). This is the first Brazilian study evaluating patients with suspected HEV infection with increased ALT levels, which were higher than 12 and 60 times the normal upper limit, in the acute phase or for patients reactive for antibody detection, respectively. Liver damage could be minimized by implementing molecular diagnostic tests in the hospital routine.

Viral load of respiratory syncytial virus among children from primary care and hospital settings admitted to a university hospital in Brazil (2009-2013).

Respiratory syncytial virus (RSV) is a relevant cause of acute respiratory infection among children. Viral replication and immune conditions may account for severity. RSV viral load (VL) was assessed in 486 children (290 hospitalized and 196 from primary care) attended at São Paulo Hospital from 2009 to 2013. VL was calculated by real-time reverse transcription-polymerase chain reaction and expressed in Log10 RNA copies/mL. Coinfection with rhinovirus (RV) and influenza A virus was also tested. Young children (<1 year of age) had a higher mean VL than older children at primary care (6.35 and 4.34 Log10 RNA copies/mL, respectively; P = .0006). Conversely, hospitalized children ≥2 years of age, presented higher mean VL compared with the same age children of primary care (6.10 and 4.26, respectively; P = .0024). RV was the most codetected virus in RSV positive patients (20% from primary care and 14% in hospitalized), and influenza A virus was found in 11% of primary care and 0.4% in hospitalized children with RSV, without RSV VL association (P = .2903). These findings may guide future therapies and immunization policies considering the role of viral load on clinical presentation among older hospitalized children and also the change of infection transmissions.