Genotypic diversity and phenotypic spectrum of infantile liver failure syndrome type 1 due to variants inLARS1

Purpose: Biallelic variants in LARS1, coding for the cytosolic leucyl-tRNA synthetase, cause infantile liver failure syndrome 1 (ILFS1). Since its description in 2012, there has been no systematic analysis of the clinical spectrum and genetic findings. Methods: Individuals with biallelic variants in LARS1 were included through an international, multicenter collaboration including novel and previously published patients. Clinical variables were analyzed and functional studies were performed in patient-derived fibroblasts. Results: Twenty-five individuals from 15 families were ascertained including 12 novel patients with eight previously unreported variants. The most prominent clinical findings are recurrent elevation of liver transaminases up to liver failure and encephalopathic episodes, both triggered by febrile illness. Magnetic resonance image (MRI) changes during an encephalopathic episode can be consistent with metabolic stroke. Furthermore, growth retardation, microcytic anemia, neurodevelopmental delay, muscular hypotonia, and infection-related seizures are prevalent. Aminoacylation activity is significantly decreased in all patient cells studied upon temperature elevation in vitro. Conclusion: ILFS1 is characterized by recurrent elevation of liver transaminases up to liver failure in conjunction with abnormalities of growth, blood, nervous system, and musculature. Encephalopathic episodes with seizures can occur independently from liver crises and may present with metabolic stroke

HIV Replication Enhances Production of Free Fatty Acids, Low Density Lipoproteins and Many Key Proteins Involved in Lipid Metabolism: A Proteomics Study

BACKGROUND: HIV-infected patients develop multiple metabolic abnormalities including insulin resistance, lipodystrophy and dyslipidemia. Although progression of these disorders has been associated with the use of various protease inhibitors and other antiretroviral drugs, HIV-infected individuals who have not received these treatments also develop lipid abnormalities albeit to a lesser extent. How HIV alters lipid metabolism in an infected cell and what molecular changes are affected through protein interaction pathways are not well-understood. RESULTS: Since many genetic, epigenetic, dietary and other factors influence lipid metabolism in vivo, we have chosen to study genome-wide changes in the proteomes of a human T-cell line before and after HIV infection in order to circumvent computational problems associated with multiple variables. Four separate experiments were conducted including one that compared 14 different time points over a period of >3 months. By subtractive analyses of protein profiles overtime, several hundred differentially expressed proteins were identified in HIV-infected cells by mass spectrometry and each protein was scrutinized for its biological functions by using various bioinformatics programs. Herein, we report 18 HIV-modulated proteins and their interaction pathways that enhance fatty acid synthesis, increase low density lipoproteins (triglycerides), dysregulate lipid transport, oxidize lipids, and alter cellular lipid metabolism. CONCLUSIONS: We conclude that HIV replication alone (i.e. without any influence of antiviral drugs, or other human genetic factors), can induce novel cellular enzymes and proteins that are significantly associated with biologically relevant processes involved in lipid synthesis, transport and metabolism (p = <0.0002-0.01). Translational and clinical studies on the newly discovered proteins may now shed light on how some of these proteins may be useful for early diagnosis of individuals who might be at high risk for developing lipid-related disorders. The target proteins could then be used for future studies in the development of inhibitors for preventing lipid-metabolic anomalies. This is the first direct evidence that HIV-modulates production of proteins that are significantly involved in disrupting the normal lipid-metabolic pathways

Dysregulation of proinflammatory versus anti-inflammatory human TH_H17 cell functionalities in the autoinflammatory Schnitzler syndrome

Background: T$_H$17 cells have so far been considered to be crucial mediators of autoimmune inflammation. Two distinct types of T$_H$17 cells have been described recently, which differed in their polarization requirement for IL-1b and in their cytokine repertoire. Whether these distinct T$_H$17 phenotypes translate into distinct T$_H$17 cell functions with implications for human health or disease has not been addressed yet. Objective: We hypothesized the existence of proinflammatory and anti-inflammatory human T$_H$17 cell functions based on the differential expression of IL-10, which is regulated by IL-1 beta. Considering the crucial role of IL-1 beta in the pathogenesis of autoinflammatory syndromes, we hypothesized that IL-1 beta mediates the loss of anti-inflammatory T$_H$17 cell functionalities in patients with Schnitzler syndrome, an autoinflammatory disease. Methods: To assess proinflammatory versus anti-inflammatory T$_H$17 cell functions, we performed suppression assays and tested the effects of IL-1 beta dependent and independent T$_H$17 subsets on modulating proinflammatory cytokine secretion by monocytes. Patients with Schnitzler syndrome were analyzed for changes in T$_H$17 cell functions before and during therapy with IL-1 beta-blocking drugs. Results: Both T$_H$17 cell subsets differ in their ability to suppress T-cell proliferation and their ability to modulate proinflammatory cytokine production by antigen-presenting cells because of their differential IL-10 expression properties. In patients with Schnitzler syndrome, systemic overproduction of IL-1 beta translates into a profound loss of anti-inflammatory T$_H$17 cell functionalities, which can be reversed by anti-IL-1b treatment. Conclusion: IL-1 beta signaling determines the differential expression pattern of IL-10, which is necessary and sufficient to induce proinflammatory versus anti-inflammatory T$_H$17 cell functions. Our data introduce T$_H$17 cell subsets as novel players in autoinflammation and thus novel therapeutic targets in autoinflammatory syndromes including other IL-1 beta mediated diseases. This demonstrates for the first time alterations in the adaptive immune system in patients with autoinflammatory syndromes

Disease severity in children and adolescents with familial Mediterranean fever: a comparative study to explore environmental effects on a monogenic disease

Background: Worldwide, familial Mediterranean fever (FMF) is the most common autoinflammatory disease. It has been suggested that environmental factors affect the phenotype as some patients do not develop the complication of secondary amyloidosis

Differences In The Severity Of The Phenotype Of Children And Adolescents With Familial Mediterranean Fever Residing In Turkey And Germany

PubMe