Clinical and myopathological characteristics of desminopathy caused by a mutation in desmin tail domain

fhl2b mediates extraocular muscle protection in zebrafish models of muscular dystrophies and its ectopic expression ameliorates affected body muscles

In muscular dystrophies, muscle fibers loose integrity and die, causing significant suffering and premature death. Strikingly, the extraocular muscles (EOMs) are spared, functioning well despite the disease progression. Although EOMs have been shown to differ from body musculature, the mechanisms underlying this inherent resistance to muscle dystrophies remain unknown. Here, we demonstrate important differences in gene expression as a response to muscle dystrophies between the EOMs and trunk muscles in zebrafish via transcriptomic profiling. We show that the LIM-protein Fhl2 is increased in response to the knockout of desmin, plectin and obscurin, cytoskeletal proteins whose knockout causes different muscle dystrophies, and contributes to disease protection of the EOMs. Moreover, we show that ectopic expression of fhl2b can partially rescue the muscle phenotype in the zebrafish Duchenne muscular dystrophy model sapje, significantly improving their survival. Therefore, Fhl2 is a protective agent and a candidate target gene for therapy of muscular dystrophies.

Phenotypic variability within the desminopathies: A case series of three patients

The DES gene encodes desmin, a key intermediate filament of skeletal, cardiac and smooth muscle. Pathogenic DES variants produce a range of skeletal and cardiac muscle disorders collectively known as the desminopathies. We report three desminopathy cases which highlight the phenotypic heterogeneity of this disorder and discuss various factors that may contribute to the clinical differences seen between patients with different desmin variants and also between family members with the same variant.

Molecular insights into cardiomyopathies associated with desmin (DES) mutations

Increasing usage of next-generation sequencing techniques pushed during the last decade cardiogenetic diagnostics leading to the identification of a huge number of genetic variants in about 170 genes associated with cardiomyopathies, channelopathies, or syndromes with cardiac involvement. Because of the biochemical and cellular complexity, it is challenging to understand the clinical meaning or even the relevant pathomechanisms of the majority of genetic sequence variants. However, detailed knowledge about the associated molecular pathomechanism is essential for the development of efficient therapeutic strategies in future and genetic counseling. Mutations in DES, encoding the muscle-specific intermediate filament protein desmin, have been identified in different kinds of cardiac and skeletal myopathies. Here, we review the functions of desmin in health and disease with a focus on cardiomyopathies. In addition, we will summarize the genetic and clinical literature about DES mutations and will explain relevant cell and animal models. Moreover, we discuss upcoming perspectives and consequences of novel experimental approaches like genome editing technology, which might open a novel research field contributing to the development of efficient and mutation-specific treatment options.

Chronic hepatitis B infection presenting with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS): a case report

Introduction

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids is a brainstem disorder characterized by perivascular pathologic reaction with lymphocyte infiltration and leading to diplopia, facial palsy, dysarthria, and gait ataxia. It was thought to be an autoimmune disorder without distinct pathogenesis. Chronic hepatitis B virus infection has been proposed in correlation with autoimmune diseases, including central nervous system demyelinating disease. Patients with chronic hepatitis B infection may develop the syndrome of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids.

Case presentation

A 34-year-old Taiwanese man who had been a hepatitis B virus carrier for a decade presented to our emergency room. He had influenza symptoms and progressive symptoms of left hemifacial numbness, double vision, and an unsteady gait of 2 days’ duration. Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids was diagnosed, with increased hepatitis B viral load at the same time. He had no past history of similar neurologic deficits, and his liver function tests had been within normal limits before this episode. After corticosteroid and entecavir treatments, his neurological deficits and neuroimaging anomalies improved and his serum hepatitis B virus DNA viral load normalized.

Conclusions

Hepatitis B virus infection may induce central nervous system autoimmune reactions, including chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids. In such cases, concomitant administration of corticosteroids and antiviral agent was helpful. We suggest further investigations in patients with regulatory T cell dysfunction, which may assist in clarifying a loss of immune tolerance in patients with such disorders.