Generation of induced Pluripotent Stem Cells as disease modelling of NLSDM.

Neutral Lipid Storage Disease with Myopathy (NLSDM) is a rare defect of triacylglycerol metabolism, characterized by the abnormal storage of neutral lipid in organelles known as lipid droplets (LDs). The main clinical features are progressive myopathy and cardiomyopathy. The onset of NLSDM is caused by autosomal recessive mutations in the PNPLA2 gene, which encodes adipose triglyceride lipase (ATGL). Despite its name, this enzyme is present in a wide variety of cell types and catalyzes the first step in triacylglycerol lipolysis and the release of fatty acids. Here, we report the derivation of NLSDM-induced pluripotent stem cells (NLSDM-iPSCs) from fibroblasts of two patients carrying different PNPLA2 mutations. The first patient was homozygous for the c.541delAC, while the second was homozygous for the c.662G>C mutation in the PNPLA2 gene. We verified that the two types of NLSDM-iPSCs possessed properties of embryonic-like stem cells and could differentiate into the three germ layers in vitro. Immunofluorescence analysis revealed that iPSCs had an abnormal accumulation of triglycerides in LDs, the hallmark of NLSDM. Furthermore, NLSDM-iPSCs were deficient in long chain fatty acid lipolysis, when subjected to a pulse chase experiment with oleic acid. Collectively, these results demonstrate that NLSDM-iPSCs are a promising in vitro model to investigate disease mechanisms and screen drug compounds for NLSDM, a rare disease with few therapeutic options.

Sensory involvement in spinal-bulbar muscular atrophy (Kennedy's disease).

Spinal-bulbar muscular atrophy (SBMA) is a rare X-linked neuronopathy associated with an abnormal representation of androgen receptors in the nervous system. Standard nerve conduction and histopathological studies have disclosed the involvement of large myelinated sensory fibers in the spinal nerves of SBMA patients. Little is known about the involvement of small sensory neurons and trigeminal nerves. Laser evoked potentials (LEPs) were studied in 6 unrelated patients with SBMA; 5 of these patients also underwent trigeminal reflex recordings, and 3 a sural nerve biopsy. LEPs were markedly abnormal, indicating a dysfunction in pain pathways. Given the sparing of small fibers in the sural nerve specimens, we hypothesize a dysfunction in spinothalamic cells, possibly due to an abnormal representation of the androgen receptors. Except for the jaw-jerk, all the trigeminal reflexes were markedly abnormal. Since the afferents for the jaw-jerk have their cell body within the central nervous system instead of the ganglion, the selective sparing of the jaw-jerk indicates a trigeminal ganglionopathy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL). Neuropathological and in vitro studies of abnormal elastogenesis.

This study was performed on a family of CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy) subjects. Neuropathological alterations of small arteries consisting in thickening, reduplication and fragmentation of the internal elastic lamella, and granular periodic acid-Schiff-positive material deposited in the arterial media were demonstrated in 1 autopsy case by histochemistry and electron microscopy. This material reacted with a monoclonal antibody anti-elastin (aE), as demonstrated by immunohistochemistry and immunoelectron microscopy. Significant increases of aE-immunoreactivity and elastin mRNA expression were found in cultured skin fibroblasts from 5 family members genetically affected by CADASIL, but not genetically and clinically healthy members. These results suggest that alterations of the elastic apparatus are associated with CADASIL genotype and related to the clinical expression of the disease.

Spongy state (status spongiosus) and inhibition of Na,K-ATPase: a pathogenetic theory.

Spongiform encephalopathies are characterized above all by spongiosis. This neuropathological characteristic is morphologically mimed by in vivo inhibition of cerebral brain Na,K-ATPase by means of subdural administration of ouabain. In this paper we underline the possibility that the 'spongiotic state' in other diseases might also be caused by the inhibition of this enzyme, thus hypothesizing that it is the enzyme itself that is targeted by the infective agent. The infective agent could, we believe, be shown to be linked to the enzyme if it were separated from the infected brain.

Immunohistological study of a case of cerebral Langerhans cell histiocytosis in brain biopsy.

Although several attempts at the immunohistochemical characterization of histiocytosis have recently been made there is only one paper which reports a case of cerebral Langerhans cell histiocytosis (LCH) diagnosed by biopsy. This paper presents a bioptically diagnosed case of juvenile histiocytosis. The panel of antibodies used was as follows: anti-S-100, 2 different antibodies to anti-interleukin 2, anti-lysozyme, anti-LEU M1, anti-MAC 387, anti-major histocompatibility complex II and anti-GFAP. Microglia markers--Griffonia simplicifolia and RCA 1 lectins were also utilized. The proliferating cells produced a positive response to S-100, lysozyme and a partially positive response to HLA DR, but responded negatively to MAC 387, LEU M1, lectins, IL2R and GFAP. Our results were compared and analyzed in the light of those obtained by other authors.