“Protein aggregates” contain RNA and DNA,entrapped by misfolded proteins but largely rescued by slowing translational elongation

All neurodegenerative diseases feature aggregates, which usually contain disease‐specific diagnostic proteins; non‐protein constituents, however, have rarely been explored. Aggregates from SY5Y‐APP_Sw neuroblastoma, a cell model of familial Alzheimer''s disease, were crosslinked and sequences of linked peptides identified. We constructed a normalized “contactome” comprising 11 subnetworks, centered on 24 high‐connectivity hubs. Remarkably, all 24 are nucleic acid‐binding proteins. This led us to isolate and sequence RNA and DNA from Alzheimer''s and control aggregates. RNA fragments were mapped to the human genome by RNA‐seq and DNA by ChIP‐seq. Nearly all aggregate RNA sequences mapped to specific genes, whereas DNA fragments were predominantly intergenic. These nucleic acid mappings are all significantly nonrandom, making an artifactual origin extremely unlikely. RNA (mostly cytoplasmic) exceeded DNA (chiefly nuclear) by twofold to fivefold. RNA fragments recovered from AD tissue were ~1.5‐to 2.5‐fold more abundant than those recovered from control tissue, similar to the increase in protein. Aggregate abundances of specific RNA sequences were strikingly differential between cultured SY5Y‐APP_Sw glioblastoma cells expressing APOE3 vs. APOE4, consistent with APOE4 competition for E‐box/CLEAR motifs. We identified many G‐quadruplex and viral sequences within RNA and DNA of aggregates, suggesting that sequestration of viral genomes may have driven the evolution of disordered nucleic acid‐binding proteins. After RNA‐interference knockdown of the translational‐procession factor EEF2 to suppress translation in SY5Y‐APP_Sw cells, the RNA content of aggregates declined by >90%, while reducing protein content by only 30% and altering DNA content by ≤10%. This implies that cotranslational misfolding of nascent proteins may ensnare polysomes into aggregates, accounting for most of their RNA content.     

Knowledge and attitudes regarding genetic testing among Jordanians: An approach towards genomic medicine

BackgroundThe twenty first century can be called the genomic era referring to the rapid development of genetics, and the beginning of genomic medicine. An initial step towards genomic medicine is to evaluate the knowledge and attitude towards genetic testing among different populations. The aims of this study were to assess the genetic knowledge and attitude towards genetic testing among the Jordanian population and patients with immune diseases. In addition, we evaluated the association between knowledge, attitude and several demographic factors of the population.MethodsThis study was performed using an online questionnaire that was distributed to respondents from different regions of Jordan.ResultsA total of 1149 participants were recruited from the Jordanian population. Overall factual genetic knowledge of the participants was good (65.4%), with education level, working or studying in a health-related field and household average monthly income being significant predictors of factual knowledge scores (P = 0.03, P < 0.001 and P < 0.001, respectively). However, factual knowledge results revealed that scores of questions related to diseases were significantly higher than scores of gene-related scientific facts (P < 0.01). Participants of our study reported to have low perceived knowledge on medical uses (39.5%) and social consequences (23.9%) of genetic testing. Regarding the participants’ attitudes, favorable attitudes towards genetic testing were prevailing (91.5%). Favorable attitudes were more prominent among higher educated participants, and participants with higher scores of factual knowledge.ConclusionDespite the fact that our Jordanian-based study revealed a good level of genetic knowledge as well as a favorable attitude towards genetic testing, we realized an imbalance of knowledge between gene-related scientific facts and disease-related concepts as well as between factual and perceived genetic knowledge, which indicates the necessity of increasing the awareness about genetic testing in order to ensure that individuals can take informed decisions that help in the employment of personalized medicine.     

Noncommunicable disease outcomes and the effects of vertical and horizontal health aid

Foreign health aid forms a substantial portion of health spending in many low- and middle-income countries (LMICs). It can be either vertical (funds earmarked for specific diseases) or horizontal (funds used for broad health sector strengthening). Historically, most health aid has been disbursed vertically toward key infectious diseases, with minimal allocations to noncommunicable diseases (NCDs). High NCD burden in LMICs underscores a need for increased assistance toward NCD objectives, but evidence on the outcomes of health aid for NCDs is sparse. We obtained annual data on cause-specific deaths and disability-adjusted life years (DALYs) for four leading NCDs across 116 countries, 2000–2016, and evaluated the relationship between these indicators and vertical and horizontal health aid using country fixed-effects models with 1-to-5-year lagged effects. After adjusting for fixed and time-variant country heterogeneity, vertical assistance for NCDs was significantly associated with subsequent reductions in NCD morbidity and mortality, particularly for persons under age 70 and for cardiovascular and chronic respiratory diseases. An additional dollar in per-capita NCD vertical assistance corresponded to reductions in the average annual NCD burden of 7,459 DALYs/281 deaths after one year, 7,728 DALYs/319 deaths after two years, and 8,957 DALYs/346 deaths after three years. The findings suggest that vertical assistance for NCD programs may be an appropriate mechanism for addressing short-term NCD needs in LMICs, where it may help to fill health sector gaps in NCD care, but longer-term evaluation is needed for assessing the role of horizontal assistance.     

A finite element model of stress-mediated vascular adaptation: application to abdominal aortic aneurysms

Despite rapid expansion of our knowledge of vascular adaptation, developing patient-specific models of diseased arteries is still an open problem. In this study, we extend existing finite element models of stress-mediated growth and remodelling of arteries to incorporate a medical image-based geometry of a healthy aorta and, then, simulate abdominal aortic aneurysm. Degradation of elastin initiates a local dilatation of the aorta while stress-mediated turnover of collagen and smooth muscle compensates the loss of elastin. Stress distributions and expansion rates during the aneurysm growth are studied for multiple spatial distribution functions of elastin degradation and kinetic parameters. Temporal variations of the degradation function are also investigated with either direct time-dependent degradation or stretch-induced degradation as possible biochemical and biomechanical mechanisms for elastin degradation. The results show that this computational model has the capability to capture the complexities of aneurysm progression due to variations of geometry, extent of damage and stress-mediated turnover as a step towards patient-specific modelling.     

Signaling pathway factors expression in renal tissue of apoE-knockout mice

Abstract

Apolipoprotein E (apoE) is regarded as one of the major plasma lipoproteins, and it plays an important role in the transport and metabolism of lipids. apoE can be found in multiple tissues, such as liver, kidney, jejunum, urinary bladder, ileum, colon, brain, adrenal glands, lung, ovary, spleen, pancreas, and testis, etc. As a secreted protein, it plays an important role in the systemic lipoprotein metabolism and vascular wall homeostasis and in the pathogenesis of renal diseases. apoE-knockout (apoE(?/?)) mice is a classic model of atherosclerosis and renal diseases. However, no review summed up the signaling pathway factors expression in renal tissue of apoE-knockout mice. The literatures were searched extensively and this review was performed to review the signaling pathway factors expression in renal tissue of apoE-knockout mice.     

Interplay of protein misfolding pathway and unfolded-protein response in acute promyelocytic leukemia

Protein misfolding has traditionally been linked to the pathogenesis of various neurodegenerative diseases. However, emerging evidence from various laboratories, including ours, suggests that protein misfolding may also play a fundamental role in some malignancies, particularly those caused by fusion oncoprotein generated from chromosomal translocation. Promyelocytic leukemia (PML) fused to the retinoic acid receptor (RAR) is a fusion oncoprotein linked to the transformation of acute promyelocytic leukemia (APL), and is not only a misfolded protein itself, but also promotes misfolding of nuclear receptor corepressor (N-CoR) protein, a corepressor essential for the growth-suppressive function of several tumor-suppressor proteins. PML–RAR promotes misfolding of N-CoR by inducing aberrant post-translational modification, which destabilizes its core and promotes instability. Misfolded N-CoR, thus, contributes to differentiation arrest and survival of APL cells through loss-of-function and aberrant gain-of-function properties. Therapeutic restoration of N-CoR conformation and function with conformation-modifying agents not only releases this differentiation arrest but also sensitizes APL cells to programmed cell death. These findings illustrate the potential of the misfolded N-CoR protein as a conformation-based drugable molecular target for APL, and highlights the promise of various conformation-modifying agents as novel therapeutics for APL. Protein conformational rearrangement, resulting from an inherited or acquired genetic alteration, could be a common pathological phenomenon contributing to transformation in different types of leukemias and solid tumors and, therefore, could serve as a common ground for designing a unifying diagnostic as well as therapeutic approach for a widely diverse disease such as cancer. To that end, APL could serve as a model for the development of a novel conformation-based therapeutic approach for other malignant diseases.     

Cortactin mediates elevated shear stress-induced mucin hypersecretion via actin polymerization in human airway epithelial cells

Mucus hypersecretion is a remarkable pathophysiological manifestation in airway obstructive diseases. These diseases are usually accompanied with elevated shear stress due to bronchoconstriction. Previous studies have reported that shear stress induces mucin5AC (MUC5AC) secretion via actin polymerization in cultured nasal epithelial cells. Furthermore, it is well known that cortactin, an actin binding protein, is a central mediator of actin polymerization. Therefore, we hypothesized that cortactin participates in MUC5AC hypersecretion induced by elevated shear stress via actin polymerization in cultured human airway epithelial cells. Compared with the relevant control groups, Src phosphorylation, cortactin phosphorylation, actin polymerization and MUC5AC secretion were significantly increased after exposure to elevated shear stress. Similar effects were found when pretreating the cells with jasplakinolide, and transfecting with wild-type cortactin. However, these effects were significantly attenuated by pretreating with Src inhibitor, cytochalasin D or transfecting cells with the specific small interfering RNA of cortactin. Collectively, these results suggest that elevated shear stress induces MUC5AC hypersecretion via tyrosine-phosphorylated cortactin-associated actin polymerization in cultured human airway epithelial cells.     

Matrix metalloproteinase (MMP)-2 and MMP-9 polymorphisms and haplotypes as disease biomarkers

Chaudhary and colleagues observed associations of matrix metalloproteinase (MMP)-2 (-1306C/T) and MMP-9 (-1562C/T) promoter polymorphisms with head and neck squamous cell carcinoma (HNSCC), but not with oral submucous fibrosis (OSMF) in an Indian population. We suggest that they could carry out a haplotype analysis with their data on MMP-2 genotypes (-1306C/T and -168G/T) and that they consider genotyping the microsatellite -90 (CA)_14–24 in the MMP-9 promoter region in order to perform haplotype analysis in combination with their data on MMP-9 (-1562C/T) polymorphism. These suggestions could provide additional information with clinical relevance to cancer susceptibility.