Pathology, classification and pathogenesis of lupus glomerulonephritis

Fine-tuning of MEK signaling is pivotal for limiting B and T cell activation

MEK1 and MEK2, the only known activators of ERK, are attractive therapeutic candidates for both cancer and autoimmune diseases. However, how MEK signaling finely regulates immune cell activation is only partially understood. To address this question, we specifically delete Mek1 in hematopoietic cells in the Mek2 null background. Characterization of an allelic series of Mek mutants reveals the presence of distinct degrees of spontaneous B cell activation, which are inversely proportional to the levels of MEK proteins and ERK activation. While Mek1 and Mek2 null mutants have a normal lifespan, 1Mek1 and 1Mek2 mutants retaining only one functional Mek1 or Mek2 allele in hematopoietic cell lineages die from glomerulonephritis and lymphoproliferative disorders, respectively. This establishes that the fine-tuning of the ERK/MAPK pathway is critical to regulate B and T cell activation and function and that each MEK isoform plays distinct roles during lymphocyte activation and disease development.

Systemic lupus erythematosus: An update for ophthalmologists

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.