Medically actionable pathogenic variants in a population of 13,131 healthy elderly individuals.

PURPOSE: To measure the prevalence of medically actionable pathogenic variants (PVs) among a population of healthy elderly individuals. METHODS: We used targeted sequencing to detect pathogenic or likely pathogenic variants in 55 genes associated with autosomal dominant medically actionable conditions, among a population of 13,131 individuals aged 70 or older (mean age 75 years) enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) trial. Participants had no previous diagnosis or current symptoms of cardiovascular disease, physical disability or dementia, and no current diagnosis of life-threatening cancer. Variant curation followed American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) standards. RESULTS: One in 75 (1.3%) healthy elderly individuals carried a PV. This was lower than rates reported from population-based studies, which have ranged from 1.8% to 3.4%. We detected 20 PV carriers for Lynch syndrome (MSH6/MLH1/MSH2/PMS2) and 13 for familial hypercholesterolemia (LDLR/APOB/PCSK9). Among 7056 female participants, we detected 15 BRCA1/BRCA2 PV carriers (1 in 470 females). We detected 86 carriers of PVs in lower-penetrance genes associated with inherited cardiac disorders. CONCLUSION: Medically actionable PVs are carried in a healthy elderly population. Our findings raise questions about the actionability of lower-penetrance genes, especially when PVs are detected in the absence of symptoms and/or family history of disease.

Cell entry of avian reovirus follows a caveolin-1-mediated and dynamin-2-dependent endocytic pathway that requires activation of p38 mitogen-activated protein kinase (MAPK) and Src signaling pathways as well as microtubules and small GTPase Rab5 protein.

Very little is known about the mechanism of cell entry of avian reovirus (ARV). The aim of this study was to explore the mechanism of ARV entry and subsequent infection. Cholesterol mainly affected the early steps of the ARV life cycle, because the presence of cholesterol before and during viral adsorption greatly blocked ARV infectivity. Although we have demonstrated that ARV facilitating p38 MAPK is beneficial for virus replication, its mechanism remains unknown. Here, we show that ARV-induced phosphorylation of caveolin-1 (Tyr(14)), dynamin-2 expression, and Rac1 activation through activation of p38 MAPK and Src in the early stage of the virus life cycle is beneficial for virus entry and productive infection. The strong inhibition by dynasore, a specific inhibitor of dynamin-2, and depletion of endogenous caveolin-1 or dynamin-2 by siRNAs as well as the caveolin-1 colocalization study implicate caveolin-1-mediated and dynamin-2-dependent endocytosis as a significant avenue of ARV entry. By means of pharmacological inhibitors, dominant negative mutants, and siRNA of various cellular proteins and signaling molecules, phosphorylation of caveolin-1, dynamin-2 expression, and Rac1 activation were suppressed, suggesting that by orchestrating p38 MAPK, Src, and Rac1 signaling cascade in the target cells, ARV creates an appropriate intracellular environment facilitating virus entry and productive infection. Furthermore, disruption of microtubules, Rab5, or endosome acidification all inhibited ARV infection, suggesting that microtubules and small GTPase Rab5, which regulate transport to early endosome, are crucial for survival of ARV and that exposure of the virus to acidic pH is required for productive infection.

Clinical significance of serum lipids in idiopathic pulmonary alveolar proteinosis.

BACKGROUND: It is well known that pulmonary alveolar proteinosis(PAP) is characterised by accumulation of surfactant lipids and proteins within airspaces. However, few previous data describe the serum lipid levels associated with PAP. MATERIALS AND METHODS: We retrospectively reviewed 25 patients with idiopathic PAP(iPAP). The serum lipid levels of patients with idiopathic PAP were compared with those of the healthy volunteers. In patients and healthy subjects, the LDL-C/HDL-C ratios were 2.94 ± 1.21 and 1.60 ± 0.70, respectively (p < 0.001), HDL-C were 1.11 ± 0.27 and 1.71 ± 0.71 respectively (p < 0.001). The values of LDL-C correlated significantly with those of PaO2 and PA-aO2 (r = -0.685, p = 0.003, and r = 0.688, p = 0.003, respectively). The values of LDL-C/HDL-C ratios also correlated with PaO2 levels and PA-aO2 levels (r = -0.698, p = 0.003, and r = 0.653, p = 0.006, respectively). 11 and 13 patients experienced respectively a decline in TC and LDL-C levels following whole lung lavage(WLL), the median decline was 0.71 mmol/L(p < 0.009) and 0.47 mmol/L(p < 0.003), respectively. CONCLUSIONS: the serum lipid levels, especially the levels of LDL-C and LDL-C/HDL-C, may reflect the severity of the disease in PAP patients, and predict the therapeutic effect of WLL.

Inhibitors of phosphatidylinositol 3-kinase and mTOR but not Akt enhance replication of bovine ephemeral fever virus.

Non-segmented, negative-sense RNA viruses (NNSVs) depend on Akt (protein kinase B) for efficient replication. Infection with bovine ephemeral fever virus (BEFV) increases Akt phosphorylation. This study examined the effect of inhibition of phosphatidylinositol 3-kinase (PI3K)-Akt signalling on BEFV replication, since PI3K is the major upstream regulator of Akt. Treatment of BEFV-infected cells with two specific PI3K inhibitors (wortmannin and LY294002) enhanced replication of BEFV when compared to the effects of Akt inhibitors III and IV. BEFV antagonised the effects of PI3K inhibitors on Akt dephosphorylation. Inhibition of mTOR by rapamycin also enhanced replication of BEFV. The results provide evidences that inhibition of PI3K and mTOR has positive effects on replication of BEFV.

Intracellular cleavage of sigmaA protein of avian reovirus.

By Western blot analyzes of expression of avian reovirus proteins, one unknown fragment was detected by an anti-sigmaA monoclonal antibody in virus-infected cells lysate. It was interesting to note that RNA interference against sigmaA resulted in the suppression of the unknown fragment. Using various lengths of sigmaA constructs conjugated with different tags, we present evidences to demonstrate that the fragment comes from the cleavage of sigmaA and is the larger carboxyl-terminus, termed sigmaAC. Cleavage of sigmaA simultaneously produces a smaller amino-terminus, named sigmaAN. sigmaAC could be seen early in viral infection and accumulated with time and dose of infection, indicating that the derived products are not just transient intermediates of protein degradation. The same type of cleaved products were also observed in different genotypes and serotypes of ARV as well as in different cell lines, suggesting that this intracellular modification of sigmaA is common to all ARVs. Similar localization of sigmaAC in both cytosol and nucleus with sigmaA suggested that further modification of sigmaA may be important for its function. Our evidences suggest that besides the outer capsid protein muB, sigmaA may also have post-translational cleavage which has never been reported before even in related mammalian reovirus.