Suppressor of lin-12-like–HMG-CoA reductase degradation 1 (SEL1L-HRD1) ER-associated degradation (ERAD) plays a critical role in many physiological processes in mice, including immunity, water homeostasis, and energy metabolism; however, its relevance and importance in humans remain unclear, as no disease variant has been identified. Here, we report a biallelic SEL1L variant (p. Cys141Tyr) in 5 patients from a consanguineous Slovakian family. These patients presented with not only ERAD-associated neurodevelopmental disorders with onset in infancy (ENDI) syndromes, but infantile-onset agammaglobulinemia with no mature B cells, resulting in frequent infections and early death. This variant disrupted the formation of a disulfide bond in the luminal fibronectin II domain of SEL1L, largely abolishing the function of the SEL1L-HRD1 ERAD complex in part via proteasomal-mediated self destruction by HRD1. This study reports a disease entity termed ENDI-agammaglobulinemia (ENDI-A) syndrome and establishes an inverse correlation between SEL1L-HRD1 ERAD functionality and disease severity in humans.
Mutations in the voltage-gated sodium channel Nav1.1 (SCN1A) are linked to various epileptic phenotypes with different severities, however, the consequences of newly identified SCN1A variants on patient phenotype is uncertain so far. The functional impact of nine SCN1A variants, including five novel variants identified in this study, was studied using whole-cell patch-clamp recordings measurement of mutant Nav1.1 channels expressed in HEK293T mammalian cells. E78X, W384X, E1587K, and R1596C channels failed to produce measurable sodium currents, indicating complete loss of channel function. E788K and M909K variants resulted in partial loss of function by exhibiting reduced current density, depolarizing shifts of the activation and hyperpolarizing shifts of the inactivation curves, and slower recovery from inactivation. Hyperpolarizing shifts of the activation and inactivation curves were observed in D249E channels along with slower recovery from inactivation. Slower recovery from inactivation was observed in E78D and T1934I with reduced current density in T1934I channels. Various functional effects were observed with the lack of sodium current being mainly associated with severe phenotypes and milder symptoms with less damaging channel alteration. In vitro functional analysis is thus fundamental for elucidation of the molecular mechanisms of epilepsy, to guide patients’ treatment, and finally indicate misdiagnosis of SCN1A related epilepsies.
1 August 2014 in Protein Expression and Purification
Despite outstanding advances in diagnosis and the treatment of primary uveal melanoma (UM), nearly 50% of UM patients develop metastases via hematogenous dissemination, driven by the epithelial-mesenchymal transition (EMT). Despite the failure in UM to date, a liquid biopsy may offer a feasible non-invasive approach for monitoring metastatic disease progression and addressing protracted dormancy. To detect circulating tumor cells (CTCs) in UM patients, we evaluated the mRNA expression of EMT-associated transcription factors in CD45-depleted blood fraction, using qRT-PCR. ddPCR was employed to assess UM-specific GNA11, GNAQ, PLCβ4, and CYSLTR2 mutations in plasma DNA. Moreover, microarray analysis was performed on total RNA isolated from tumor tissues to estimate the prognostic value of EMT-associated gene expression. In total, 42 primary UM and 11 metastatic patients were enrolled. All CD45-depleted samples were negative for CTC when compared to the peripheral blood fraction of 60 healthy controls. Tumor-specific mutations were detected in the plasma of 21.4% patients, merely, in 9.4% of primary UM, while 54.5% in metastatic patients. Unsupervised hierarchical clustering of differentially expressed EMT genes showed significant differences between monosomy 3 and disomy 3 tumors. Newly identified genes can serve as non-invasive prognostic biomarkers that can support therapeutic decisions.
The growing production of nanomaterials and their presence in consumer products raises fear about their impact on human health and the environment. Of particular concern are those nanomaterials that exhibit poor excretion and tend to accumulate in living organisms. Our study investigated the potential adverse biological effects of residual gold and titania nanoparticles (PEG-AuNPs and TiO2NPs) 28 days after a single intravenous administration in rats. To comprehensively assess the potential health hazard of these metal nanoparticles (MNP), toxicological and transcriptomic analyses were employed. The liver was the primary organ of the MNP deposition, causing a reduction in the relative liver weight compared to unexposed animals. Concurrently, changes in serum biomarkers indicative of hepatic dysfunction and hematological and immunological alternations were determined. Integrated transcriptomic analysis unveiled exposure-induced effects on the rats' lungs, liver, and kidneys. The hepatic tissue, particularly in PEG-AuNPs-exposed rats, exhibited a noteworthy prevalence of deregulated genes, with functional classification spanning lipid metabolism, cell cycle, and cell proliferation pathways. Although the number of deregulated miRNAs was relatively modest compared to mRNA expression changes, both types of MNPs deregulated miR-203a, associated with liver injury, and miR-18a-5p and miR-32-5p linked to kidney damage. This study underscores the imperative for a more exhaustive biosafety assessment of poorly soluble MNPs that tend to deposit in the body. Such investigations are crucial for delineating the potential risks of these nanomaterials and guiding the development of adequate safety measures in their production and usage.